1
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Barrier J, Kim M, Kumar RK, Xin N, Kumaravadivel P, Hague L, Nguyen E, Berdyugin AI, Moulsdale C, Enaldiev VV, Prance JR, Koppens FHL, Gorbachev RV, Watanabe K, Taniguchi T, Glazman LI, Grigorieva IV, Fal'ko VI, Geim AK. One-dimensional proximity superconductivity in the quantum Hall regime. Nature 2024; 628:741-745. [PMID: 38658686 DOI: 10.1038/s41586-024-07271-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 03/05/2024] [Indexed: 04/26/2024]
Abstract
Extensive efforts have been undertaken to combine superconductivity and the quantum Hall effect so that Cooper-pair transport between superconducting electrodes in Josephson junctions is mediated by one-dimensional edge states1-6. This interest has been motivated by prospects of finding new physics, including topologically protected quasiparticles7-9, but also extends into metrology and device applications10-13. So far it has proven challenging to achieve detectable supercurrents through quantum Hall conductors2,3,6. Here we show that domain walls in minimally twisted bilayer graphene14-18 support exceptionally robust proximity superconductivity in the quantum Hall regime, allowing Josephson junctions to operate in fields close to the upper critical field of superconducting electrodes. The critical current is found to be non-oscillatory and practically unchanging over the entire range of quantizing fields, with its value being limited by the quantum conductance of ballistic, strictly one-dimensional, electronic channels residing within the domain walls. The system described is unique in its ability to support Andreev bound states at quantizing fields and offers many interesting directions for further exploration.
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Affiliation(s)
- Julien Barrier
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
| | - Minsoo Kim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- Department of Applied Physics, Kyung Hee University, Yong-in, South Korea
| | - Roshan Krishna Kumar
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Na Xin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- Department of Chemistry, Zhejiang University, Hangzhou, China.
| | - P Kumaravadivel
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Lee Hague
- National Graphene Institute, University of Manchester, Manchester, UK
| | - E Nguyen
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - A I Berdyugin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Christian Moulsdale
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - V V Enaldiev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - J R Prance
- Department of Physics, Lancaster University, Lancaster, UK
| | - F H L Koppens
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - R V Gorbachev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - K Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - T Taniguchi
- National Institute for Materials Science, Tsukuba, Japan
| | - L I Glazman
- Department of Physics, Yale University, New Haven, CT, USA
| | - I V Grigorieva
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - V I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK
| | - A K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
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2
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de Vries F, Slizovskiy S, Tomić P, Krishna Kumar R, Garcia-Ruiz A, Zheng G, Portolés E, Ponomarenko LA, Geim AK, Watanabe K, Taniguchi T, Fal’ko V, Ensslin K, Ihn T, Rickhaus P. Kagome Quantum Oscillations in Graphene Superlattices. Nano Lett 2024; 24:601-606. [PMID: 38180909 PMCID: PMC10797620 DOI: 10.1021/acs.nanolett.3c03524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/17/2023] [Accepted: 12/19/2023] [Indexed: 01/07/2024]
Abstract
Electronic spectra of solids subjected to a magnetic field are often discussed in terms of Landau levels and Hofstadter-butterfly-style Brown-Zak minibands manifested by magneto-oscillations in two-dimensional electron systems. Here, we present the semiclassical precursors of these quantum magneto-oscillations which appear in graphene superlattices at low magnetic field near the Lifshitz transitions and persist at elevated temperatures. These oscillations originate from Aharonov-Bohm interference of electron waves following open trajectories that belong to a kagome-shaped network of paths characteristic for Lifshitz transitions in the moire superlattice minibands of twistronic graphenes.
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Affiliation(s)
| | - Sergey Slizovskiy
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, United Kingdom
| | - Petar Tomić
- Laboratory
for Solid State Physics, ETH Zürich, Zürich CH-8093, Switzerland
| | - Roshan Krishna Kumar
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, United Kingdom
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, Barcelona 08028, Spain
| | - Aitor Garcia-Ruiz
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, United Kingdom
| | - Giulia Zheng
- Laboratory
for Solid State Physics, ETH Zürich, Zürich CH-8093, Switzerland
| | - Elías Portolés
- Laboratory
for Solid State Physics, ETH Zürich, Zürich CH-8093, Switzerland
| | | | - Andre K. Geim
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, United Kingdom
| | - Kenji Watanabe
- National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Vladimir Fal’ko
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, United Kingdom
- Henry
Royce
Institute for Advanced Materials, Manchester M13 9PL, United Kingdom
| | - Klaus Ensslin
- Laboratory
for Solid State Physics, ETH Zürich, Zürich CH-8093, Switzerland
| | - Thomas Ihn
- Laboratory
for Solid State Physics, ETH Zürich, Zürich CH-8093, Switzerland
| | - Peter Rickhaus
- Laboratory
for Solid State Physics, ETH Zürich, Zürich CH-8093, Switzerland
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3
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Dufils T, Schran C, Chen J, Geim AK, Fumagalli L, Michaelides A. Origin of dielectric polarization suppression in confined water from first principles. Chem Sci 2024; 15:516-527. [PMID: 38179530 PMCID: PMC10763014 DOI: 10.1039/d3sc04740g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/23/2023] [Indexed: 01/06/2024] Open
Abstract
It has long been known that the dielectric constant of confined water should be different from that in bulk. Recent experiments have shown that it is vanishingly small, however the origin of the phenomenon remains unclear. Here we used ab initio molecular dynamics simulations (AIMD) and AIMD-trained machine-learning potentials to understand water's structure and electronic properties underpinning this effect. For the graphene and hexagonal boron-nitride substrates considered, we find that it originates in the spontaneous anti-parallel alignment of the water dipoles in the first two water layers near the solid interface. The interfacial layers exhibit net ferroelectric ordering, resulting in an overall anti-ferroelectric arrangement of confined water. Together with constrained hydrogen-bonding orientations, this leads to much reduced out-of-plane polarization. Furthermore, we directly contrast AIMD and simple classical force-field simulations, revealing important differences. This work offers insight into a property of water that is critical in modulating surface forces, the electric-double-layer formation and molecular solvation, and shows a way to compute it.
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Affiliation(s)
- T Dufils
- Department of Physics and Astronomy, University of Manchester Manchester M13 9PL UK
- National Graphene Institute, University of Manchester Manchester M13 9PL UK
| | - C Schran
- Cavendish Laboratory, Department of Physics, University of Cambridge Cambridge CB3 0HE UK
- Lennard-Jones Centre, University of Cambridge Trinity Ln Cambridge CB2 1TN UK
| | - J Chen
- School of Physics, Peking University Beijing 100871 China
| | - A K Geim
- Department of Physics and Astronomy, University of Manchester Manchester M13 9PL UK
- National Graphene Institute, University of Manchester Manchester M13 9PL UK
| | - L Fumagalli
- Department of Physics and Astronomy, University of Manchester Manchester M13 9PL UK
- National Graphene Institute, University of Manchester Manchester M13 9PL UK
| | - A Michaelides
- Lennard-Jones Centre, University of Cambridge Trinity Ln Cambridge CB2 1TN UK
- Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
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4
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Ronceray N, Spina M, Chou VHY, Lim CT, Geim AK, Garaj S. Elastocapillarity-driven 2D nano-switches enable zeptoliter-scale liquid encapsulation. Nat Commun 2024; 15:185. [PMID: 38167702 PMCID: PMC10762047 DOI: 10.1038/s41467-023-44200-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 12/03/2023] [Indexed: 01/05/2024] Open
Abstract
Biological nanostructures change their shape and function in response to external stimuli, and significant efforts have been made to design artificial biomimicking devices operating on similar principles. In this work we demonstrate a programmable nanofluidic switch, driven by elastocapillarity, and based on nanochannels built from layered two-dimensional nanomaterials possessing atomically smooth surfaces and exceptional mechanical properties. We explore operational modes of the nanoswitch and develop a theoretical framework to explain the phenomenon. By predicting the switching-reversibility phase diagram-based on material, interfacial and wetting properties, as well as the geometry of the nanofluidic circuit-we rationally design switchable nano-capsules capable of enclosing zeptoliter volumes of liquid, as small as the volumes enclosed in viruses. The nanoswitch will find useful application as an active element in integrated nanofluidic circuitry and could be used to explore nanoconfined chemistry and biochemistry, or be incorporated into shape-programmable materials.
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Affiliation(s)
- Nathan Ronceray
- Department of Physics, National University of Singapore, Singapore, 117551, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117542, Singapore
| | - Massimo Spina
- Department of Physics, National University of Singapore, Singapore, 117551, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117542, Singapore
| | - Vanessa Hui Yin Chou
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117542, Singapore
| | - Chwee Teck Lim
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
- Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore, 119276, Singapore
- Mechanobiology Institute, National University of Singapore, Singapore, 117411, Singapore
| | - Andre K Geim
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Slaven Garaj
- Department of Physics, National University of Singapore, Singapore, 117551, Singapore.
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117542, Singapore.
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore.
- Department of Material Science Engineering, National University of Singapore, Singapore, 117575, Singapore.
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5
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Zhou L, Yang C, Yang X, Zhang J, Wang C, Wang W, Li M, Lu X, Li K, Yang H, Zhou H, Chen J, Zhan D, Fal'ko VI, Cheng J, Tian Z, Geim AK, Cao Y, Hu S. Angstrom-Scale Electrochemistry at Electrodes with Dimensions Commensurable and Smaller than Individual Reacting Species. Angew Chem Int Ed Engl 2023; 62:e202314537. [PMID: 37966039 DOI: 10.1002/anie.202314537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/26/2023] [Accepted: 11/14/2023] [Indexed: 11/16/2023]
Abstract
In nature and technologies, many chemical reactions occur at interfaces with dimensions approaching that of a single reacting species in nano- and angstrom-scale. Mechanisms governing reactions at this ultimately small spatial regime remain poorly explored because of challenges to controllably fabricate required devices and assess their performance in experiment. Here we report how efficiency of electrochemical reactions evolves for electrodes that range from just one atom in thickness to sizes comparable with and exceeding hydration diameters of reactant species. The electrodes are made by encapsulating graphene and its multilayers within insulating crystals so that only graphene edges remain exposed and partake in reactions. We find that limiting current densities characterizing electrochemical reactions exhibit a pronounced size effect if reactant's hydration diameter becomes commensurable with electrodes' thickness. An unexpected blockade effect is further revealed from electrodes smaller than reactants, where incoming reactants are blocked by those adsorbed temporarily at the atomically narrow interfaces. The demonstrated angstrom-scale electrochemistry offers a venue for studies of interfacial behaviors at the true molecular scale.
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Affiliation(s)
- Lijun Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Chongyang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Xiaohui Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Jie Zhang
- School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, 411201, P. R. China
| | - Cong Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Wei Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Mengyan Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Xiangchao Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Ke Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Huiping Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Han Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Jiajia Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Dongping Zhan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Vladimir I Fal'ko
- Department of Physics and Astronomy, the University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, the University of Manchester, Manchester, M13 9PL, UK
| | - Jun Cheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Zhongqun Tian
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Andre K Geim
- Department of Physics and Astronomy, the University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, the University of Manchester, Manchester, M13 9PL, UK
| | - Yang Cao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, 361005, P. R. China
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, P. R. China
| | - Sheng Hu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, 361005, P. R. China
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, P. R. China
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6
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Wu ZF, Sun PZ, Wahab OJ, Tan YT, Barry D, Periyanagounder D, Pillai PB, Dai Q, Xiong WQ, Vega LF, Lulla K, Yuan SJ, Nair RR, Daviddi E, Unwin PR, Geim AK, Lozada-Hidalgo M. Proton and molecular permeation through the basal plane of monolayer graphene oxide. Nat Commun 2023; 14:7756. [PMID: 38012200 PMCID: PMC10682477 DOI: 10.1038/s41467-023-43637-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 11/15/2023] [Indexed: 11/29/2023] Open
Abstract
Two-dimensional (2D) materials offer a prospect of membranes that combine negligible gas permeability with high proton conductivity and could outperform the existing proton exchange membranes used in various applications including fuel cells. Graphene oxide (GO), a well-known 2D material, facilitates rapid proton transport along its basal plane but proton conductivity across it remains unknown. It is also often presumed that individual GO monolayers contain a large density of nanoscale pinholes that lead to considerable gas leakage across the GO basal plane. Here we show that relatively large, micrometer-scale areas of monolayer GO are impermeable to gases, including helium, while exhibiting proton conductivity through the basal plane which is nearly two orders of magnitude higher than that of graphene. These findings provide insights into the key properties of GO and demonstrate that chemical functionalization of 2D crystals can be utilized to enhance their proton transparency without compromising gas impermeability.
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Affiliation(s)
- Z F Wu
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - P Z Sun
- Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau, 999078, China.
| | - O J Wahab
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Y T Tan
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - D Barry
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - D Periyanagounder
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - P B Pillai
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
- Department of Chemical Engineering, The University of Manchester, Manchester, M13 9PL, UK
| | - Q Dai
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - W Q Xiong
- Key Laboratory of Artificial Micro- and Nano-structures of the Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - L F Vega
- Research and Innovation Center on CO2 and Hydrogen (RICH Center) and Chemical Engineering Department, Khalifa University, PO Box 127788, Abu Dhabi, United Arab Emirates
- Research and Innovation Center for graphene and 2D materials (RIC2D), Khalifa University, PO Box 127788, Abu Dhabi, United Arab Emirates
| | - K Lulla
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - S J Yuan
- Key Laboratory of Artificial Micro- and Nano-structures of the Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - R R Nair
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
- Department of Chemical Engineering, The University of Manchester, Manchester, M13 9PL, UK
| | - E Daviddi
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - P R Unwin
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom.
| | - A K Geim
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.
| | - M Lozada-Hidalgo
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.
- Research and Innovation Center for graphene and 2D materials (RIC2D), Khalifa University, PO Box 127788, Abu Dhabi, United Arab Emirates.
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7
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Mullan C, Slizovskiy S, Yin J, Wang Z, Yang Q, Xu S, Yang Y, Piot BA, Hu S, Taniguchi T, Watanabe K, Novoselov KS, Geim AK, Fal'ko VI, Mishchenko A. Mixing of moiré-surface and bulk states in graphite. Nature 2023; 620:756-761. [PMID: 37468634 PMCID: PMC10447246 DOI: 10.1038/s41586-023-06264-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 05/25/2023] [Indexed: 07/21/2023]
Abstract
Van der Waals assembly enables the design of electronic states in two-dimensional (2D) materials, often by superimposing a long-wavelength periodic potential on a crystal lattice using moiré superlattices1-9. This twistronics approach has resulted in numerous previously undescribed physics, including strong correlations and superconductivity in twisted bilayer graphene10-12, resonant excitons, charge ordering and Wigner crystallization in transition-metal chalcogenide moiré structures13-18 and Hofstadter's butterfly spectra and Brown-Zak quantum oscillations in graphene superlattices19-22. Moreover, twistronics has been used to modify near-surface states at the interface between van der Waals crystals23,24. Here we show that electronic states in three-dimensional (3D) crystals such as graphite can be tuned by a superlattice potential occurring at the interface with another crystal-namely, crystallographically aligned hexagonal boron nitride. This alignment results in several Lifshitz transitions and Brown-Zak oscillations arising from near-surface states, whereas, in high magnetic fields, fractal states of Hofstadter's butterfly draw deep into the bulk of graphite. Our work shows a way in which 3D spectra can be controlled using the approach of 2D twistronics.
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Affiliation(s)
- Ciaran Mullan
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Sergey Slizovskiy
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Jun Yin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
| | - Ziwei Wang
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Qian Yang
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Shuigang Xu
- National Graphene Institute, University of Manchester, Manchester, UK
- Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science, Westlake University, Hangzhou, China
| | - Yaping Yang
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Benjamin A Piot
- Laboratoire National des Champs Magnétiques Intenses (LNCMI), CNRS Université Grenoble Alpes, Université Toulouse 3, INSA Toulouse, EMFL, Grenoble, France
| | - Sheng Hu
- National Graphene Institute, University of Manchester, Manchester, UK
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | | | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - Kostya S Novoselov
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, Singapore
| | - A K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Vladimir I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
- Henry Royce Institute for Advanced Materials, Manchester, UK.
| | - Artem Mishchenko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
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8
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Wahab OJ, Daviddi E, Xin B, Sun PZ, Griffin E, Colburn AW, Barry D, Yagmurcukardes M, Peeters FM, Geim AK, Lozada-Hidalgo M, Unwin PR. Proton transport through nanoscale corrugations in two-dimensional crystals. Nature 2023; 620:782-786. [PMID: 37612394 PMCID: PMC10447238 DOI: 10.1038/s41586-023-06247-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/23/2023] [Indexed: 08/25/2023]
Abstract
Defect-free graphene is impermeable to all atoms1-5 and ions6,7 under ambient conditions. Experiments that can resolve gas flows of a few atoms per hour through micrometre-sized membranes found that monocrystalline graphene is completely impermeable to helium, the smallest atom2,5. Such membranes were also shown to be impermeable to all ions, including the smallest one, lithium6,7. By contrast, graphene was reported to be highly permeable to protons, nuclei of hydrogen atoms8,9. There is no consensus, however, either on the mechanism behind the unexpectedly high proton permeability10-14 or even on whether it requires defects in graphene's crystal lattice6,8,15-17. Here, using high-resolution scanning electrochemical cell microscopy, we show that, although proton permeation through mechanically exfoliated monolayers of graphene and hexagonal boron nitride cannot be attributed to any structural defects, nanoscale non-flatness of two-dimensional membranes greatly facilitates proton transport. The spatial distribution of proton currents visualized by scanning electrochemical cell microscopy reveals marked inhomogeneities that are strongly correlated with nanoscale wrinkles and other features where strain is accumulated. Our results highlight nanoscale morphology as an important parameter enabling proton transport through two-dimensional crystals, mostly considered and modelled as flat, and indicate that strain and curvature can be used as additional degrees of freedom to control the proton permeability of two-dimensional materials.
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Affiliation(s)
- O J Wahab
- Department of Chemistry, University of Warwick, Coventry, UK
| | - E Daviddi
- Department of Chemistry, University of Warwick, Coventry, UK
| | - B Xin
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK
- National Graphene Institute, The University of Manchester, Manchester, UK
| | - P Z Sun
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK
- National Graphene Institute, The University of Manchester, Manchester, UK
| | - E Griffin
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK
- National Graphene Institute, The University of Manchester, Manchester, UK
| | - A W Colburn
- Department of Chemistry, University of Warwick, Coventry, UK
| | - D Barry
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - M Yagmurcukardes
- Department of Photonics, Izmir Institute of Technology, Urla, Turkey
| | - F M Peeters
- Departement Fysica, Universiteit Antwerpen, Antwerp, Belgium
- Departamento de Fisica, Universidade Federal do Ceara, Fortaleza, Brazil
| | - A K Geim
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK.
- National Graphene Institute, The University of Manchester, Manchester, UK.
| | - M Lozada-Hidalgo
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK.
- National Graphene Institute, The University of Manchester, Manchester, UK.
| | - P R Unwin
- Department of Chemistry, University of Warwick, Coventry, UK.
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9
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Xin N, Lourembam J, Kumaravadivel P, Kazantsev AE, Wu Z, Mullan C, Barrier J, Geim AA, Grigorieva IV, Mishchenko A, Principi A, Fal'ko VI, Ponomarenko LA, Geim AK, Berdyugin AI. Giant magnetoresistance of Dirac plasma in high-mobility graphene. Nature 2023; 616:270-274. [PMID: 37045919 PMCID: PMC10097601 DOI: 10.1038/s41586-023-05807-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 02/08/2023] [Indexed: 04/14/2023]
Abstract
The most recognizable feature of graphene's electronic spectrum is its Dirac point, around which interesting phenomena tend to cluster. At low temperatures, the intrinsic behaviour in this regime is often obscured by charge inhomogeneity1,2 but thermal excitations can overcome the disorder at elevated temperatures and create an electron-hole plasma of Dirac fermions. The Dirac plasma has been found to exhibit unusual properties, including quantum-critical scattering3-5 and hydrodynamic flow6-8. However, little is known about the plasma's behaviour in magnetic fields. Here we report magnetotransport in this quantum-critical regime. In low fields, the plasma exhibits giant parabolic magnetoresistivity reaching more than 100 per cent in a magnetic field of 0.1 tesla at room temperature. This is orders-of-magnitude higher than magnetoresistivity found in any other system at such temperatures. We show that this behaviour is unique to monolayer graphene, being underpinned by its massless spectrum and ultrahigh mobility, despite frequent (Planckian limit) scattering3-5,9-14. With the onset of Landau quantization in a magnetic field of a few tesla, where the electron-hole plasma resides entirely on the zeroth Landau level, giant linear magnetoresistivity emerges. It is nearly independent of temperature and can be suppressed by proximity screening15, indicating a many-body origin. Clear parallels with magnetotransport in strange metals12-14 and so-called quantum linear magnetoresistance predicted for Weyl metals16 offer an interesting opportunity to further explore relevant physics using this well defined quantum-critical two-dimensional system.
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Affiliation(s)
- Na Xin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - James Lourembam
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Piranavan Kumaravadivel
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - A E Kazantsev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Zefei Wu
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Ciaran Mullan
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Julien Barrier
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Alexandra A Geim
- National Graphene Institute, University of Manchester, Manchester, UK
| | - I V Grigorieva
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - A Mishchenko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - A Principi
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - V I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - L A Ponomarenko
- Department of Physics, University of Lancaster, Lancaster, UK.
| | - A K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
- Department of Materials Science and Engineering, National University of Singapore, Singapore, Singapore.
| | - Alexey I Berdyugin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
- Department of Materials Science and Engineering, National University of Singapore, Singapore, Singapore.
- Department of Physics, National University of Singapore, Singapore, Singapore.
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10
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Robin P, Emmerich T, Ismail A, Niguès A, You Y, Nam GH, Keerthi A, Siria A, Geim AK, Radha B, Bocquet L. Long-term memory and synapse-like dynamics in two-dimensional nanofluidic channels. Science 2023; 379:161-167. [PMID: 36634187 DOI: 10.1126/science.adc9931] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Fine-tuned ion transport across nanoscale pores is key to many biological processes, including neurotransmission. Recent advances have enabled the confinement of water and ions to two dimensions, unveiling transport properties inaccessible at larger scales and triggering hopes of reproducing the ionic machinery of biological systems. Here we report experiments demonstrating the emergence of memory in the transport of aqueous electrolytes across (sub)nanoscale channels. We unveil two types of nanofluidic memristors depending on channel material and confinement, with memory ranging from minutes to hours. We explain how large time scales could emerge from interfacial processes such as ionic self-assembly or surface adsorption. Such behavior allowed us to implement Hebbian learning with nanofluidic systems. This result lays the foundation for biomimetic computations on aqueous electrolytic chips.
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Affiliation(s)
- P Robin
- Laboratoire de Physique de l'Ecole normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, France
| | - T Emmerich
- Laboratoire de Physique de l'Ecole normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, France
| | - A Ismail
- National Graphene Institute, The University of Manchester, Manchester, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - A Niguès
- Laboratoire de Physique de l'Ecole normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, France
| | - Y You
- National Graphene Institute, The University of Manchester, Manchester, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - G-H Nam
- National Graphene Institute, The University of Manchester, Manchester, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - A Keerthi
- National Graphene Institute, The University of Manchester, Manchester, UK.,Department of Chemistry, The University of Manchester, Manchester, UK
| | - A Siria
- Laboratoire de Physique de l'Ecole normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, France
| | - A K Geim
- National Graphene Institute, The University of Manchester, Manchester, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - B Radha
- National Graphene Institute, The University of Manchester, Manchester, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - L Bocquet
- Laboratoire de Physique de l'Ecole normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, France
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11
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Cai J, Griffin E, Guarochico-Moreira V, Barry D, Xin B, Huang S, Geim AK, Peeters FM, Lozada-Hidalgo M. Photoaccelerated Water Dissociation Across One-Atom-Thick Electrodes. Nano Lett 2022; 22:9566-9570. [PMID: 36449567 PMCID: PMC9756329 DOI: 10.1021/acs.nanolett.2c03701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Recent experiments demonstrated that interfacial water dissociation (H2O ⇆ H+ + OH-) could be accelerated exponentially by an electric field applied to graphene electrodes, a phenomenon related to the Wien effect. Here we report an order-of-magnitude acceleration of the interfacial water dissociation reaction under visible-light illumination. This process is accompanied by spatial separation of protons and hydroxide ions across one-atom-thick graphene and enhanced by strong interfacial electric fields. The found photoeffect is attributed to the combination of graphene's perfect selectivity with respect to protons, which prevents proton-hydroxide recombination, and to proton transport acceleration by the Wien effect, which occurs in synchrony with the water dissociation reaction. Our findings provide fundamental insights into ion dynamics near atomically thin proton-selective interfaces and suggest that strong interfacial fields can enhance and tune very fast ionic processes, which is of relevance for applications in photocatalysis and designing reconfigurable materials.
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Affiliation(s)
- Junhao Cai
- National
Graphene Institute, The University of Manchester, Manchester M13 9PL, U.K.
- Department
of Physics and Astronomy, The University
of Manchester, Manchester M13 9PL, U.K.
- College
of Advanced Interdisciplinary Studies, National
University of Defense Technology, Changsha, Hunan 410073, China
| | - Eoin Griffin
- National
Graphene Institute, The University of Manchester, Manchester M13 9PL, U.K.
- Department
of Physics and Astronomy, The University
of Manchester, Manchester M13 9PL, U.K.
| | - Victor Guarochico-Moreira
- National
Graphene Institute, The University of Manchester, Manchester M13 9PL, U.K.
- Department
of Physics and Astronomy, The University
of Manchester, Manchester M13 9PL, U.K.
- Escuela
Superior Politécnica del Litoral, ESPOL, Facultad de Ciencias Naturales y Matemáticas, P.O. Box 09-01-5863, Guayaquil, Ecuador
| | - Donnchadh Barry
- National
Graphene Institute, The University of Manchester, Manchester M13 9PL, U.K.
| | - Benhao Xin
- National
Graphene Institute, The University of Manchester, Manchester M13 9PL, U.K.
- Department
of Physics and Astronomy, The University
of Manchester, Manchester M13 9PL, U.K.
| | - Shiqi Huang
- National
Graphene Institute, The University of Manchester, Manchester M13 9PL, U.K.
- Department
of Physics and Astronomy, The University
of Manchester, Manchester M13 9PL, U.K.
| | - Andre K. Geim
- National
Graphene Institute, The University of Manchester, Manchester M13 9PL, U.K.
- Department
of Physics and Astronomy, The University
of Manchester, Manchester M13 9PL, U.K.
| | - Francois. M. Peeters
- Departement
Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Marcelo Lozada-Hidalgo
- National
Graphene Institute, The University of Manchester, Manchester M13 9PL, U.K.
- Department
of Physics and Astronomy, The University
of Manchester, Manchester M13 9PL, U.K.
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12
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Cai J, Griffin E, Guarochico-Moreira VH, Barry D, Xin B, Yagmurcukardes M, Zhang S, Geim AK, Peeters FM, Lozada-Hidalgo M. Wien effect in interfacial water dissociation through proton-permeable graphene electrodes. Nat Commun 2022; 13:5776. [PMID: 36182944 PMCID: PMC9526707 DOI: 10.1038/s41467-022-33451-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/20/2022] [Indexed: 11/09/2022] Open
Abstract
Strong electric fields can accelerate molecular dissociation reactions. The phenomenon known as the Wien effect was previously observed using high-voltage electrolysis cells that produced fields of about 107 V m-1, sufficient to accelerate the dissociation of weakly bound molecules (e.g., organics and weak electrolytes). The observation of the Wien effect for the common case of water dissociation (H2O [Formula: see text] H+ + OH-) has remained elusive. Here we study the dissociation of interfacial water adjacent to proton-permeable graphene electrodes and observe strong acceleration of the reaction in fields reaching above 108 V m-1. The use of graphene electrodes allows measuring the proton currents arising exclusively from the dissociation of interfacial water, while the electric field driving the reaction is monitored through the carrier density induced in graphene by the same field. The observed exponential increase in proton currents is in quantitative agreement with Onsager's theory. Our results also demonstrate that graphene electrodes can be valuable for the investigation of various interfacial phenomena involving proton transport.
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Affiliation(s)
- J Cai
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.,College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, Hunan, 410073, China
| | - E Griffin
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - V H Guarochico-Moreira
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.,Escuela Superior Politécnica del Litoral, ESPOL, Facultad de Ciencias Naturales y Matemáticas, P.O. Box 09-01-5863, Guayaquil, Ecuador
| | - D Barry
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - B Xin
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - M Yagmurcukardes
- Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020, Antwerp, Belgium.,Department of Photonics, Izmir Institute of Technology, 35430, Izmir, Urla, Turkey
| | - S Zhang
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - A K Geim
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.,Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117546, Singapore
| | - F M Peeters
- Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020, Antwerp, Belgium
| | - M Lozada-Hidalgo
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK. .,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
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13
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Kumar C, Birkbeck J, Sulpizio JA, Perello D, Taniguchi T, Watanabe K, Reuven O, Scaffidi T, Stern A, Geim AK, Ilani S. Imaging hydrodynamic electrons flowing without Landauer-Sharvin resistance. Nature 2022; 609:276-281. [PMID: 36071191 DOI: 10.1038/s41586-022-05002-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 06/21/2022] [Indexed: 11/09/2022]
Abstract
Electrical resistance usually originates from lattice imperfections. However, even a perfect lattice has a fundamental resistance limit, given by the Landauer1 conductance caused by a finite number of propagating electron modes. This resistance, shown by Sharvin2 to appear at the contacts of electronic devices, sets the ultimate conduction limit of non-interacting electrons. Recent years have seen growing evidence of hydrodynamic electronic phenomena3-18, prompting recent theories19,20 to ask whether an electronic fluid can radically break the fundamental Landauer-Sharvin limit. Here, we use single-electron-transistor imaging of electronic flow in high-mobility graphene Corbino disk devices to answer this question. First, by imaging ballistic flows at liquid-helium temperatures, we observe a Landauer-Sharvin resistance that does not appear at the contacts but is instead distributed throughout the bulk. This underpins the phase-space origin of this resistance-as emerging from spatial gradients in the number of conduction modes. At elevated temperatures, by identifying and accounting for electron-phonon scattering, we show the details of the purely hydrodynamic flow. Strikingly, we find that electron hydrodynamics eliminates the bulk Landauer-Sharvin resistance. Finally, by imaging spiralling magneto-hydrodynamic Corbino flows, we show the key emergent length scale predicted by hydrodynamic theories-the Gurzhi length. These observations demonstrate that electronic fluids can dramatically transcend the fundamental limitations of ballistic electrons, with important implications for fundamental science and future technologies.
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Affiliation(s)
- C Kumar
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - J Birkbeck
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - J A Sulpizio
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - D Perello
- School of Physics & Astronomy, University of Manchester, Manchester, UK.,National Graphene Institute, University of Manchester, Manchester, UK
| | - T Taniguchi
- National Institute for Materials Science, Tsukuba, Japan
| | - K Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - O Reuven
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - T Scaffidi
- Department of Physics, University of Toronto, Toronto, ON, Canada.,Department of Physics and Astronomy, University of California, Irvine, CA, USA
| | - Ady Stern
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - A K Geim
- School of Physics & Astronomy, University of Manchester, Manchester, UK.,National Graphene Institute, University of Manchester, Manchester, UK
| | - S Ilani
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel.
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14
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Achari A, Bekaert J, Sreepal V, Orekhov A, Kumaravadivel P, Kim M, Gauquelin N, Balakrishna Pillai P, Verbeeck J, Peeters FM, Geim AK, Milošević MV, Nair RR. Alternating Superconducting and Charge Density Wave Monolayers within Bulk 6R-TaS 2. Nano Lett 2022; 22:6268-6275. [PMID: 35857927 PMCID: PMC9373026 DOI: 10.1021/acs.nanolett.2c01851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Van der Waals (vdW) heterostructures continue to attract intense interest as a route of designing materials with novel properties that cannot be found in nature. Unfortunately, this approach is currently limited to only a few layers that can be stacked on top of each other. Here, we report a bulk vdW material consisting of superconducting 1H TaS2 monolayers interlayered with 1T TaS2 monolayers displaying charge density waves (CDW). This bulk vdW heterostructure is created by phase transition of 1T-TaS2 to 6R at 800 °C in an inert atmosphere. Its superconducting transition (Tc) is found at 2.6 K, exceeding the Tc of the bulk 2H phase. Using first-principles calculations, we argue that the coexistence of superconductivity and CDW within 6R-TaS2 stems from amalgamation of the properties of adjacent 1H and 1T monolayers, where the former dominates the superconducting state and the latter the CDW behavior.
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Affiliation(s)
- Amritroop Achari
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Chemical Engineering, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Jonas Bekaert
- Department
of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium
- NANOlab
Center of Excellence, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Vishnu Sreepal
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Chemical Engineering, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Andrey Orekhov
- NANOlab
Center of Excellence, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
- Electron
Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Piranavan Kumaravadivel
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, United Kingdom
| | - Minsoo Kim
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, United Kingdom
| | - Nicolas Gauquelin
- NANOlab
Center of Excellence, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
- Electron
Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Premlal Balakrishna Pillai
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Chemical Engineering, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Johan Verbeeck
- NANOlab
Center of Excellence, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
- Electron
Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Francois M. Peeters
- Department
of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium
| | - Andre K. Geim
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, United Kingdom
| | - Milorad V. Milošević
- Department
of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium
- NANOlab
Center of Excellence, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Rahul R. Nair
- National
Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department
of Chemical Engineering, University of Manchester, Manchester M13 9PL, United Kingdom
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15
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Zhou Z, Tan Y, Yang Q, Bera A, Xiong Z, Yagmurcukardes M, Kim M, Zou Y, Wang G, Mishchenko A, Timokhin I, Wang C, Wang H, Yang C, Lu Y, Boya R, Liao H, Haigh S, Liu H, Peeters FM, Li Y, Geim AK, Hu S. Gas permeation through graphdiyne-based nanoporous membranes. Nat Commun 2022; 13:4031. [PMID: 35821120 PMCID: PMC9276745 DOI: 10.1038/s41467-022-31779-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 07/01/2022] [Indexed: 12/11/2022] Open
Abstract
Nanoporous membranes based on two dimensional materials are predicted to provide highly selective gas transport in combination with extreme permeance. Here we investigate membranes made from multilayer graphdiyne, a graphene-like crystal with a larger unit cell. Despite being nearly a hundred of nanometers thick, the membranes allow fast, Knudsen-type permeation of light gases such as helium and hydrogen whereas heavy noble gases like xenon exhibit strongly suppressed flows. Using isotope and cryogenic temperature measurements, the seemingly conflicting characteristics are explained by a high density of straight-through holes (direct porosity of ∼0.1%), in which heavy atoms are adsorbed on the walls, partially blocking Knudsen flows. Our work offers important insights into intricate transport mechanisms playing a role at nanoscale. 2D nanoporous membranes are predicted to provide highly selective gas transport in combination with extreme permeance. Here authors demonstrate gas separation performance and transport mechanisms through membranes of graphdiyne, a quasi 2D material with a graphene-like structure.
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Affiliation(s)
- Zhihua Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Yongtao Tan
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Qian Yang
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Achintya Bera
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Zecheng Xiong
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | | | - Minsoo Kim
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Yichao Zou
- Department of Materials, University of Manchester, Manchester, M13 9PL, UK
| | - Guanghua Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Artem Mishchenko
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Ivan Timokhin
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Canbin Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Hao Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Chongyang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Yizhen Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Radha Boya
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Honggang Liao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Sarah Haigh
- Department of Materials, University of Manchester, Manchester, M13 9PL, UK
| | - Huibiao Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Francois M Peeters
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium
| | - Yuliang Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China. .,University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
| | - Andre K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK. .,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK.
| | - Sheng Hu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.
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16
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Huang Z, Lan T, Dai L, Zhao X, Wang Z, Zhang Z, Li B, Li J, Liu J, Ding B, Geim AK, Cheng HM, Liu B. 2D Functional Minerals as Sustainable Materials for Magneto-Optics. Adv Mater 2022; 34:e2110464. [PMID: 35084782 DOI: 10.1002/adma.202110464] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/18/2022] [Indexed: 06/14/2023]
Abstract
Liquid crystal devices using organic molecules are nowadays widely used to modulate transmitted light, but this technology still suffers from relatively weak response, high cost, toxicity and environmental concerns, and cannot fully meet the demand of future sustainable society. Here, an alternative approach to color-tunable optical devices, which is based on sustainable inorganic liquid crystals derived from 2D mineral materials abundant in nature, is described. The prototypical 2D mineral of vermiculite is massively produced by a green method, possessing size-to-thickness aspect ratios of >103 , in-plane magnetization of >10 emu g-1 , and an optical bandgap of >3 eV. These characteristics endow 2D vermiculite with sensitive magneto-birefringence response, been several orders of magnitude larger than organic counterparts, as well as capability of broad-spectrum modulation. The finding consequently permits the fabrication of various magnetochromic or mechanochromic devices with low or even zero-energy consumption during operation. This work creates opportunities for the application of sustainable materials in advanced optics.
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Affiliation(s)
- Ziyang Huang
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
| | - Tianshu Lan
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
| | - Lixin Dai
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
| | - Xueting Zhao
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China
- School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, 110016, P. R. China
| | - Zhongyue Wang
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
| | - Zehao Zhang
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
| | - Bing Li
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China
- School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, 110016, P. R. China
| | - Jialiang Li
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, 100083, P. R. China
| | - Jingao Liu
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, 100083, P. R. China
| | - Baofu Ding
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
- Faculty of Materials Science and Engineering, Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, P. R. China
| | - Andre K Geim
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, U.K
| | - Hui-Ming Cheng
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China
- Faculty of Materials Science and Engineering, Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, P. R. China
- Advanced Technology Institute, University of Surrey, Guildford, GU2 7XH, U.K
| | - Bilu Liu
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China
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17
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Weston A, Castanon EG, Enaldiev V, Ferreira F, Bhattacharjee S, Xu S, Corte-León H, Wu Z, Clark N, Summerfield A, Hashimoto T, Gao Y, Wang W, Hamer M, Read H, Fumagalli L, Kretinin AV, Haigh SJ, Kazakova O, Geim AK, Fal'ko VI, Gorbachev R. Interfacial ferroelectricity in marginally twisted 2D semiconductors. Nat Nanotechnol 2022; 17:390-395. [PMID: 35210566 PMCID: PMC9018412 DOI: 10.1038/s41565-022-01072-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 01/04/2022] [Indexed: 05/19/2023]
Abstract
Twisted heterostructures of two-dimensional crystals offer almost unlimited scope for the design of new metamaterials. Here we demonstrate a room temperature ferroelectric semiconductor that is assembled using mono- or few-layer MoS2. These van der Waals heterostructures feature broken inversion symmetry, which, together with the asymmetry of atomic arrangement at the interface of two 2D crystals, enables ferroelectric domains with alternating out-of-plane polarization arranged into a twist-controlled network. The last can be moved by applying out-of-plane electrical fields, as visualized in situ using channelling contrast electron microscopy. The observed interfacial charge transfer, movement of domain walls and their bending rigidity agree well with theoretical calculations. Furthermore, we demonstrate proof-of-principle field-effect transistors, where the channel resistance exhibits a pronounced hysteresis governed by pinning of ferroelectric domain walls. Our results show a potential avenue towards room temperature electronic and optoelectronic semiconductor devices with built-in ferroelectric memory functions.
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Affiliation(s)
- Astrid Weston
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | | | - Vladimir Enaldiev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
- Kotel'nikov Institute of Radio-engineering and Electronics, Russian Academy of Sciences, Moscow, Russia
| | - Fábio Ferreira
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Shubhadeep Bhattacharjee
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Shuigang Xu
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | | | - Zefei Wu
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Nicholas Clark
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Materials, University of Manchester, Manchester, UK
| | - Alex Summerfield
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Teruo Hashimoto
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Materials, University of Manchester, Manchester, UK
| | - Yunze Gao
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Wendong Wang
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Matthew Hamer
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Harriet Read
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Laura Fumagalli
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Andrey V Kretinin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Materials, University of Manchester, Manchester, UK
| | - Sarah J Haigh
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Materials, University of Manchester, Manchester, UK
| | | | - A K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Vladimir I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK.
| | - Roman Gorbachev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK.
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18
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Abraham J, Vasu KS, Williams CD, Gopinadhan K, Su Y, Cherian CT, Dix J, Prestat E, Haigh SJ, Grigorieva IV, Carbone P, Geim AK, R Nair R. Reply to: Random interstratification in hydrated graphene oxide membranes and implications for seawater desalination. Nat Nanotechnol 2022; 17:134-135. [PMID: 35058652 DOI: 10.1038/s41565-021-01067-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Affiliation(s)
- Jijo Abraham
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Kalangi S Vasu
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Christopher D Williams
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Kalon Gopinadhan
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Yang Su
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Christie T Cherian
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - James Dix
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Eric Prestat
- Department of Materials, University of Manchester, Manchester, UK
| | - Sarah J Haigh
- Department of Materials, University of Manchester, Manchester, UK
| | - Irina V Grigorieva
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Paola Carbone
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Andre K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Rahul R Nair
- National Graphene Institute, University of Manchester, Manchester, UK.
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK.
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19
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Berdyugin AI, Xin N, Gao H, Slizovskiy S, Dong Z, Bhattacharjee S, Kumaravadivel P, Xu S, Ponomarenko LA, Holwill M, Bandurin DA, Kim M, Cao Y, Greenaway MT, Novoselov KS, Grigorieva IV, Watanabe K, Taniguchi T, Fal'ko VI, Levitov LS, Kumar RK, Geim AK. Out-of-equilibrium criticalities in graphene superlattices. Science 2022; 375:430-433. [PMID: 35084955 DOI: 10.1126/science.abi8627] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In thermodynamic equilibrium, current in metallic systems is carried by electronic states near the Fermi energy, whereas the filled bands underneath contribute little to conduction. Here, we describe a very different regime in which carrier distribution in graphene and its superlattices is shifted so far from equilibrium that the filled bands start playing an essential role, leading to a critical-current behavior. The criticalities develop upon the velocity of electron flow reaching the Fermi velocity. Key signatures of the out-of-equilibrium state are current-voltage characteristics that resemble those of superconductors, sharp peaks in differential resistance, sign reversal of the Hall effect, and a marked anomaly caused by the Schwinger-like production of hot electron-hole plasma. The observed behavior is expected to be common to all graphene-based superlattices.
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Affiliation(s)
- Alexey I Berdyugin
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Na Xin
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Haoyang Gao
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sergey Slizovskiy
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Zhiyu Dong
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Shubhadeep Bhattacharjee
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - P Kumaravadivel
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Shuigang Xu
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - L A Ponomarenko
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,Department of Physics, University of Lancaster, Lancaster LA1 4YW, UK
| | - Matthew Holwill
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - D A Bandurin
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Minsoo Kim
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Yang Cao
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - M T Greenaway
- Department of Physics, Loughborough University, Loughborough LE11 3TU, UK.,School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - K S Novoselov
- National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - I V Grigorieva
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - V I Fal'ko
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK.,Henry Royce Institute for Advanced Materials, Manchester M13 9PL, UK
| | - L S Levitov
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Roshan Krishna Kumar
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK.,Institut de Ciencies Fotoniques (ICFO), Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - A K Geim
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
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20
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Greenaway MT, Kumaravadivel P, Wengraf J, Ponomarenko LA, Berdyugin AI, Li J, Edgar JH, Kumar RK, Geim AK, Eaves L. Graphene's non-equilibrium fermions reveal Doppler-shifted magnetophonon resonances accompanied by Mach supersonic and Landau velocity effects. Nat Commun 2021; 12:6392. [PMID: 34737289 PMCID: PMC8568928 DOI: 10.1038/s41467-021-26663-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 10/15/2021] [Indexed: 11/21/2022] Open
Abstract
Oscillatory magnetoresistance measurements on graphene have revealed a wealth of novel physics. These phenomena are typically studied at low currents. At high currents, electrons are driven far from equilibrium with the atomic lattice vibrations so that their kinetic energy can exceed the thermal energy of the phonons. Here, we report three non-equilibrium phenomena in monolayer graphene at high currents: (i) a “Doppler-like” shift and splitting of the frequencies of the transverse acoustic (TA) phonons emitted when the electrons undergo inter-Landau level (LL) transitions; (ii) an intra-LL Mach effect with the emission of TA phonons when the electrons approach supersonic speed, and (iii) the onset of elastic inter-LL transitions at a critical carrier drift velocity, analogous to the superfluid Landau velocity. All three quantum phenomena can be unified in a single resonance equation. They offer avenues for research on out-of-equilibrium phenomena in other two-dimensional fermion systems. Magneto-oscillations have revealed many interesting phenomena in graphene and quantum Hall systems, but they are typically measured at low currents and in equilibrium. Here, the authors report several non-equilibrium quantum effects observed in magneto-oscillations in graphene at high currents.
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Affiliation(s)
- M T Greenaway
- Department of Physics, Loughborough University, Loughborough, LE11 3TU, UK. .,School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
| | - P Kumaravadivel
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - J Wengraf
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,Department of Physics, University of Lancaster, Lancaster, LA1 4YW, UK
| | - L A Ponomarenko
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,Department of Physics, University of Lancaster, Lancaster, LA1 4YW, UK
| | - A I Berdyugin
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - J Li
- Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, KS, 66506, USA
| | - J H Edgar
- Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, KS, 66506, USA
| | - R Krishna Kumar
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - A K Geim
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - L Eaves
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK. .,School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.
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21
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Kuang W, Lopez-Polin G, Lee H, Guinea F, Whitehead G, Timokhin I, Berdyugin AI, Kumar RK, Yazyev OV, Walet N, Principi A, Geim AK, Grigorieva IV. Magnetization Signature of Topological Surface States in a Non-Symmorphic Superconductor. Adv Mater 2021; 33:e2103257. [PMID: 34365697 DOI: 10.1002/adma.202103257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/16/2021] [Indexed: 06/13/2023]
Abstract
Superconductors with nontrivial band structure topology represent a class of materials with unconventional and potentially useful properties. Recent years have seen much success in creating artificial hybrid structures exhibiting the main characteristics of 2D topological superconductors. Yet, bulk materials known to combine inherent superconductivity with nontrivial topology remain scarce, largely because distinguishing their central characteristic-the topological surface states-has proved challenging due to a dominant contribution from the superconducting bulk. In this work, a highly anomalous behavior of surface superconductivity in topologically nontrivial 3D superconductor In2 Bi, where the surface states result from its nontrivial band structure, itself a consequence of the non-symmorphic crystal symmetry and strong spin-orbit coupling, is reported. In contrast to smoothly decreasing diamagnetic susceptibility above the bulk critical field, Hc2 , as seen in conventional superconductors, a near-perfect, Meissner-like screening of low-frequency magnetic fields well above Hc2 is observed. The enhanced diamagnetism disappears at a new phase transition close to the critical field of surface superconductivity, Hc3 . Using theoretical modeling, the anomalous screening is shown to be consistent with modification of surface superconductivity by the topological surface states. The possibility of detecting signatures of the surface states using macroscopic magnetization provides a new tool for the discovery and identification of topological superconductors.
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Affiliation(s)
- Wenjun Kuang
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Guillermo Lopez-Polin
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Hyungjun Lee
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH-1015, Switzerland
| | - Francisco Guinea
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - George Whitehead
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK
| | - Ivan Timokhin
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Alexey I Berdyugin
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Roshan Krishna Kumar
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Oleg V Yazyev
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH-1015, Switzerland
| | - Niels Walet
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Alessandro Principi
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Andre K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Irina V Grigorieva
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
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22
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Affiliation(s)
- Andre K Geim
- National Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
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23
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Slizovskiy S, Garcia-Ruiz A, Berdyugin A, Xin N, Taniguchi T, Watanabe K, Geim AK, Drummond ND, Fal’ko V. Out-of-Plane Dielectric Susceptibility of Graphene in Twistronic and Bernal Bilayers. Nano Lett 2021; 21:6678-6683. [PMID: 34296602 PMCID: PMC8361429 DOI: 10.1021/acs.nanolett.1c02211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 07/14/2021] [Indexed: 05/27/2023]
Abstract
We describe how the out-of-plane dielectric polarizability of monolayer graphene influences the electrostatics of bilayer graphene-both Bernal (BLG) and twisted (tBLG). We compare the polarizability value computed using density functional theory with the output from previously published experimental data on the electrostatically controlled interlayer asymmetry potential in BLG and data on the on-layer density distribution in tBLG. We show that monolayers in tBLG are described well by polarizability αexp = 10.8 Å3 and effective out-of-plane dielectric susceptibility ϵz = 2.5, including their on-layer electron density distribution at zero magnetic field and the interlayer Landau level pinning at quantizing magnetic fields.
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Affiliation(s)
- Sergey Slizovskiy
- National
Graphene Institute, University of Manchester, Booth St.E., M13 9PL Manchester, U.K.
- Dept.
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | - Aitor Garcia-Ruiz
- National
Graphene Institute, University of Manchester, Booth St.E., M13 9PL Manchester, U.K.
- Dept.
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | - Alexey
I. Berdyugin
- National
Graphene Institute, University of Manchester, Booth St.E., M13 9PL Manchester, U.K.
- Dept.
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | - Na Xin
- National
Graphene Institute, University of Manchester, Booth St.E., M13 9PL Manchester, U.K.
- Dept.
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | - Takashi Taniguchi
- National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Andre K. Geim
- National
Graphene Institute, University of Manchester, Booth St.E., M13 9PL Manchester, U.K.
- Dept.
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | - Neil D. Drummond
- Department
of Physics, Lancaster University, Lancaster LA1 4YB, U.K.
| | - Vladimir
I. Fal’ko
- National
Graphene Institute, University of Manchester, Booth St.E., M13 9PL Manchester, U.K.
- Dept.
of Physics & Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
- Henry
Royce Institute for Advanced Materials, Manchester M13 9PL, U.K.
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24
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Aharon-Steinberg A, Marguerite A, Perello DJ, Bagani K, Holder T, Myasoedov Y, Levitov LS, Geim AK, Zeldov E. Long-range nontopological edge currents in charge-neutral graphene. Nature 2021; 593:528-534. [PMID: 34040212 DOI: 10.1038/s41586-021-03501-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 03/26/2021] [Indexed: 11/09/2022]
Abstract
Van der Waals heterostructures display numerous unique electronic properties. Nonlocal measurements, wherein a voltage is measured at contacts placed far away from the expected classical flow of charge carriers, have been widely used in the search for novel transport mechanisms, including dissipationless spin and valley transport1-9, topological charge-neutral currents10-12, hydrodynamic flows13 and helical edge modes14-16. Monolayer1-5,10,15-19, bilayer9,11,14,20 and few-layer21 graphene, transition-metal dichalcogenides6,7 and moiré superlattices8,10,12 have been found to display pronounced nonlocal effects. However, the origin of these effects is hotly debated3,11,17,22-24. Graphene, in particular, exhibits giant nonlocality at charge neutrality1,15-19, a striking behaviour that has attracted competing explanations. Using a superconducting quantum interference device on a tip (SQUID-on-tip) for nanoscale thermal and scanning gate imaging25, here we demonstrate that the commonly occurring charge accumulation at graphene edges23,26-31 leads to giant nonlocality, producing narrow conductive channels that support long-range currents. Unexpectedly, although the edge conductance has little effect on the current flow in zero magnetic field, it leads to field-induced decoupling between edge and bulk transport at moderate fields. The resulting giant nonlocality at charge neutrality and away from it produces exotic flow patterns that are sensitive to edge disorder, in which charges can flow against the global electric field. The observed one-dimensional edge transport is generic and nontopological and is expected to support nonlocal transport in many electronic systems, offering insight into the numerous controversies and linking them to long-range guided electronic states at system edges.
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Affiliation(s)
- A Aharon-Steinberg
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - A Marguerite
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - D J Perello
- National Graphene Institute and School of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - K Bagani
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - T Holder
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Y Myasoedov
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - L S Levitov
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - A K Geim
- National Graphene Institute and School of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - E Zeldov
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel.
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25
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Gayduchenko I, Xu SG, Alymov G, Moskotin M, Tretyakov I, Taniguchi T, Watanabe K, Goltsman G, Geim AK, Fedorov G, Svintsov D, Bandurin DA. Tunnel field-effect transistors for sensitive terahertz detection. Nat Commun 2021; 12:543. [PMID: 33483488 PMCID: PMC7822863 DOI: 10.1038/s41467-020-20721-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/16/2020] [Indexed: 11/09/2022] Open
Abstract
The rectification of electromagnetic waves to direct currents is a crucial process for energy harvesting, beyond-5G wireless communications, ultra-fast science, and observational astronomy. As the radiation frequency is raised to the sub-terahertz (THz) domain, ac-to-dc conversion by conventional electronics becomes challenging and requires alternative rectification protocols. Here, we address this challenge by tunnel field-effect transistors made of bilayer graphene (BLG). Taking advantage of BLG's electrically tunable band structure, we create a lateral tunnel junction and couple it to an antenna exposed to THz radiation. The incoming radiation is then down-converted by the tunnel junction nonlinearity, resulting in high responsivity (>4 kV/W) and low-noise (0.2 pW/[Formula: see text]) detection. We demonstrate how switching from intraband Ohmic to interband tunneling regime can raise detectors' responsivity by few orders of magnitude, in agreement with the developed theory. Our work demonstrates a potential application of tunnel transistors for THz detection and reveals BLG as a promising platform therefor.
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Affiliation(s)
- I Gayduchenko
- Physics Department, Moscow Pedagogical State University, Moscow, 119435, Russia.,Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, 141700, Russia
| | - S G Xu
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - G Alymov
- Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, 141700, Russia
| | - M Moskotin
- Physics Department, Moscow Pedagogical State University, Moscow, 119435, Russia.,Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, 141700, Russia
| | - I Tretyakov
- Astro Space Center, Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, 117997, Russia
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute of Material Science, Tsukuba, 305-0044, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute of Material Science, Tsukuba, 305-0044, Japan
| | - G Goltsman
- Physics Department, Moscow Pedagogical State University, Moscow, 119435, Russia.,National Research University Higher School of Economics, Moscow, 101000, Russia
| | - A K Geim
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - G Fedorov
- Physics Department, Moscow Pedagogical State University, Moscow, 119435, Russia. .,Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, 141700, Russia.
| | - D Svintsov
- Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, 141700, Russia.
| | - D A Bandurin
- Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, 141700, Russia. .,School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. .,Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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26
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Woods CR, Ares P, Nevison-Andrews H, Holwill MJ, Fabregas R, Guinea F, Geim AK, Novoselov KS, Walet NR, Fumagalli L. Charge-polarized interfacial superlattices in marginally twisted hexagonal boron nitride. Nat Commun 2021; 12:347. [PMID: 33436620 PMCID: PMC7804449 DOI: 10.1038/s41467-020-20667-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/08/2020] [Indexed: 11/30/2022] Open
Abstract
When two-dimensional crystals are brought into close proximity, their interaction results in reconstruction of electronic spectrum and crystal structure. Such reconstruction strongly depends on the twist angle between the crystals, which has received growing attention due to interesting electronic and optical properties that arise in graphene and transitional metal dichalcogenides. Here we study two insulating crystals of hexagonal boron nitride stacked at small twist angle. Using electrostatic force microscopy, we observe ferroelectric-like domains arranged in triangular superlattices with a large surface potential. The observation is attributed to interfacial elastic deformations that result in out-of-plane dipoles formed by pairs of boron and nitrogen atoms belonging to opposite interfacial surfaces. This creates a bilayer-thick ferroelectric with oppositely polarized (BN and NB) dipoles in neighbouring domains, in agreement with our modeling. These findings open up possibilities for designing van der Waals heterostructures and offer an alternative probe to study moiré-superlattice electrostatic potentials.
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Affiliation(s)
- C R Woods
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK.
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK.
| | - P Ares
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - H Nevison-Andrews
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - M J Holwill
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - R Fabregas
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - F Guinea
- Imdea Nanociencia, Faraday 9, 28049, Madrid, Spain
- Donostia International Physics Center, Paseo Manuel de Lardizabal, 4, 20018, Donostia-San Sebastian, Spain
| | - A K Geim
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - K S Novoselov
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117546, Singapore
- Chongqing 2D Materials Institute, Liangjiang New Area, 400714, Chongqing, China
| | - N R Walet
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - L Fumagalli
- Department of Physics & Astronomy, University of Manchester, Manchester, M13 9PL, UK.
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK.
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27
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Wang H, Su L, Yagmurcukardes M, Chen J, Jiang Y, Li Z, Quan A, Peeters FM, Wang C, Geim AK, Hu S. Blue Energy Conversion from Holey-Graphene-like Membranes with a High Density of Subnanometer Pores. Nano Lett 2020; 20:8634-8639. [PMID: 33179495 DOI: 10.1021/acs.nanolett.0c03342] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Blue energy converts the chemical potential difference from salinity gradients into electricity via reverse electrodialysis and provides a renewable source of clean energy. To achieve high energy conversion efficiency and power density, nanoporous membrane materials with both high ionic conductivity and ion selectivity are required. Here, we report ion transport through a network of holey-graphene-like sheets made by bottom-up polymerization. The resulting ultrathin membranes provide controlled pores of <10 Å in diameter with an estimated density of about 1012 cm-2. The pores' interior contains NH2 groups that become electrically charged with varying pH and allow tunable ion selectivity. Using the holey-graphene-like membranes, we demonstrate power outputs reaching hundreds of watts per square meter. The work shows a viable route toward creating membranes with high-density angstrom-scale pores, which can be used for energy generation, ion separation, and related technologies.
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Affiliation(s)
- Hao Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Liangmei Su
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | | | - Jiawei Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Yu Jiang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Zhe Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Anchang Quan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | | | - Cheng Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Andre K Geim
- School of Physics & Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Sheng Hu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, P. R. China
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28
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Yang Y, Li J, Yin J, Xu S, Mullan C, Taniguchi T, Watanabe K, Geim AK, Novoselov KS, Mishchenko A. In situ manipulation of van der Waals heterostructures for twistronics. Sci Adv 2020; 6:eabd3655. [PMID: 33277256 PMCID: PMC7717928 DOI: 10.1126/sciadv.abd3655] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 10/22/2020] [Indexed: 05/30/2023]
Abstract
In van der Waals heterostructures, electronic bands of two-dimensional (2D) materials, their nontrivial topology, and electron-electron interactions can be markedly changed by a moiré pattern induced by twist angles between different layers. This process is referred to as twistronics, where the tuning of twist angle can be realized through mechanical manipulation of 2D materials. Here, we demonstrate an experimental technique that can achieve in situ dynamical rotation and manipulation of 2D materials in van der Waals heterostructures. Using this technique, we fabricated heterostructures where graphene is perfectly aligned with both top and bottom encapsulating layers of hexagonal boron nitride. Our technique enables twisted 2D material systems in one single stack with dynamically tunable optical, mechanical, and electronic properties.
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Affiliation(s)
- Yaping Yang
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
- National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Jidong Li
- State Key Laboratory of Mechanics and Control of Mechanical Structures and MOE Key Laboratory for Intelligent Nano Materials and Devices, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Jun Yin
- State Key Laboratory of Mechanics and Control of Mechanical Structures and MOE Key Laboratory for Intelligent Nano Materials and Devices, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Shuigang Xu
- National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Ciaran Mullan
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Andre K Geim
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
- National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Konstantin S Novoselov
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
- National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
- Centre for Advanced 2D Materials, National University of Singapore, 117546, Singapore
| | - Artem Mishchenko
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
- National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
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29
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Barrier J, Kumaravadivel P, Krishna Kumar R, Ponomarenko LA, Xin N, Holwill M, Mullan C, Kim M, Gorbachev RV, Thompson MD, Prance JR, Taniguchi T, Watanabe K, Grigorieva IV, Novoselov KS, Mishchenko A, Fal'ko VI, Geim AK, Berdyugin AI. Long-range ballistic transport of Brown-Zak fermions in graphene superlattices. Nat Commun 2020; 11:5756. [PMID: 33188210 PMCID: PMC7666116 DOI: 10.1038/s41467-020-19604-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/30/2020] [Indexed: 11/12/2022] Open
Abstract
In quantizing magnetic fields, graphene superlattices exhibit a complex fractal spectrum often referred to as the Hofstadter butterfly. It can be viewed as a collection of Landau levels that arise from quantization of Brown-Zak minibands recurring at rational (p/q) fractions of the magnetic flux quantum per superlattice unit cell. Here we show that, in graphene-on-boron-nitride superlattices, Brown-Zak fermions can exhibit mobilities above 106 cm2 V−1 s−1 and the mean free path exceeding several micrometers. The exceptional quality of our devices allows us to show that Brown-Zak minibands are 4q times degenerate and all the degeneracies (spin, valley and mini-valley) can be lifted by exchange interactions below 1 K. We also found negative bend resistance at 1/q fractions for electrical probes placed as far as several micrometers apart. The latter observation highlights the fact that Brown-Zak fermions are Bloch quasiparticles propagating in high fields along straight trajectories, just like electrons in zero field. Here, the authors show that Brown-Zak fermions in graphene-on-boron-nitride superlattices exhibit mobilities above 106 cm2/V s and micrometer scale ballistic transport.
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Affiliation(s)
- Julien Barrier
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Piranavan Kumaravadivel
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Roshan Krishna Kumar
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - L A Ponomarenko
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,Department of Physics, University of Lancaster, Lancaster, LA1 4YW, UK
| | - Na Xin
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Matthew Holwill
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Ciaran Mullan
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Minsoo Kim
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - R V Gorbachev
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - M D Thompson
- Department of Physics, University of Lancaster, Lancaster, LA1 4YW, UK
| | - J R Prance
- Department of Physics, University of Lancaster, Lancaster, LA1 4YW, UK
| | - T Taniguchi
- National Institute for Materials Science, Ibaraki, 305-0044, Japan
| | - K Watanabe
- National Institute for Materials Science, Ibaraki, 305-0044, Japan
| | - I V Grigorieva
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - K S Novoselov
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - A Mishchenko
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - V I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - A K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK. .,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK.
| | - A I Berdyugin
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK. .,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK.
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30
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Mao J, Milovanović SP, Anđelković M, Lai X, Cao Y, Watanabe K, Taniguchi T, Covaci L, Peeters FM, Geim AK, Jiang Y, Andrei EY. Evidence of flat bands and correlated states in buckled graphene superlattices. Nature 2020; 584:215-220. [DOI: 10.1038/s41586-020-2567-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 06/16/2020] [Indexed: 11/09/2022]
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31
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Ding B, Kuang W, Pan Y, Grigorieva IV, Geim AK, Liu B, Cheng HM. Giant magneto-birefringence effect and tuneable colouration of 2D crystal suspensions. Nat Commun 2020; 11:3725. [PMID: 32709947 PMCID: PMC7381639 DOI: 10.1038/s41467-020-17589-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 07/03/2020] [Indexed: 11/16/2022] Open
Abstract
One of the long-sought-after goals in light manipulation is tuning of transmitted interference colours. Previous approaches toward this goal include material chirality, strain and electric-field controls. Alternatively, colour control by magnetic field offers contactless, non-invasive and energy-free advantages but has remained elusive due to feeble magneto-birefringence in conventional transparent media. Here we demonstrate an anomalously large magneto-birefringence effect in transparent suspensions of magnetic two-dimensional crystals, which arises from a combination of a large Cotton-Mouton coefficient and relatively high magnetic saturation birefringence. The effect is orders of magnitude stronger than those previously demonstrated for transparent materials. The transmitted colours of the suspension can be continuously tuned over two-wavelength cycles by moderate magnetic fields below 0.8 T. The work opens a new avenue to tune transmitted colours, and can be further extended to other systems with artificially engineered magnetic birefringence.
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Affiliation(s)
- Baofu Ding
- Tsinghua-Berkeley Shenzhen Institute and Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Wenjun Kuang
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - Yikun Pan
- Tsinghua-Berkeley Shenzhen Institute and Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - I V Grigorieva
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - A K Geim
- Tsinghua-Berkeley Shenzhen Institute and Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China.
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.
| | - Bilu Liu
- Tsinghua-Berkeley Shenzhen Institute and Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China.
| | - Hui-Ming Cheng
- Tsinghua-Berkeley Shenzhen Institute and Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China.
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China.
- Advanced Technology Institute, University of Surrey, Guildford, Surrey, GU2 7XH, UK.
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32
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Griffin E, Mogg L, Hao GP, Kalon G, Bacaksiz C, Lopez-Polin G, Zhou TY, Guarochico V, Cai J, Neumann C, Winter A, Mohn M, Lee JH, Lin J, Kaiser U, Grigorieva IV, Suenaga K, Özyilmaz B, Cheng HM, Ren W, Turchanin A, Peeters FM, Geim AK, Lozada-Hidalgo M. Proton and Li-Ion Permeation through Graphene with Eight-Atom-Ring Defects. ACS Nano 2020; 14:7280-7286. [PMID: 32427466 DOI: 10.1021/acsnano.0c02496] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Defect-free graphene is impermeable to gases and liquids but highly permeable to thermal protons. Atomic-scale defects such as vacancies, grain boundaries, and Stone-Wales defects are predicted to enhance graphene's proton permeability and may even allow small ions through, whereas larger species such as gas molecules should remain blocked. These expectations have so far remained untested in experiment. Here, we show that atomically thin carbon films with a high density of atomic-scale defects continue blocking all molecular transport, but their proton permeability becomes ∼1000 times higher than that of defect-free graphene. Lithium ions can also permeate through such disordered graphene. The enhanced proton and ion permeability is attributed to a high density of eight-carbon-atom rings. The latter pose approximately twice lower energy barriers for incoming protons compared to that of the six-atom rings of graphene and a relatively low barrier of ∼0.6 eV for Li ions. Our findings suggest that disordered graphene could be of interest as membranes and protective barriers in various Li-ion and hydrogen technologies.
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Affiliation(s)
- Eoin Griffin
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Lucas Mogg
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Guang-Ping Hao
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Gopinadhan Kalon
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
- Department of Physics, Indian Institute of Technology Gandhinagar, Gujarat 382355, India
| | - Cihan Bacaksiz
- Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Guillermo Lopez-Polin
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - T Y Zhou
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Victor Guarochico
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Junhao Cai
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Christof Neumann
- Institute of Physical Chemistry and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Andreas Winter
- Institute of Physical Chemistry and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Michael Mohn
- Central Facility for Electron Microscopy, Electron Microscopy Group of Materials Science, Ulm University, Ulm 89081, Germany
| | - Jong Hak Lee
- Department of Physics, Department of Materials Science and Engineering & Centre for Advanced 2D Materials, National University of Singapore, Singapore 119260
| | - Junhao Lin
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan & Department of Mechanical Engineering, The University of Tokyo, Bunkyo City, Tokyo 100-8921, Japan
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Ute Kaiser
- Central Facility for Electron Microscopy, Electron Microscopy Group of Materials Science, Ulm University, Ulm 89081, Germany
| | - Irina V Grigorieva
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Kazu Suenaga
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan & Department of Mechanical Engineering, The University of Tokyo, Bunkyo City, Tokyo 100-8921, Japan
| | - Barbaros Özyilmaz
- Department of Physics, Department of Materials Science and Engineering & Centre for Advanced 2D Materials, National University of Singapore, Singapore 119260
| | - Hui-Min Cheng
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
- Shenzhen Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
| | - Wencai Ren
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Andrey Turchanin
- Institute of Physical Chemistry and Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Francois M Peeters
- Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Andre K Geim
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Marcelo Lozada-Hidalgo
- Department of Physics and Astronomy & National Graphene Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
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33
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Kim M, Xu SG, Berdyugin AI, Principi A, Slizovskiy S, Xin N, Kumaravadivel P, Kuang W, Hamer M, Kumar RK, Gorbachev RV, Watanabe K, Taniguchi T, Grigorieva IV, Fal'ko VI, Polini M, Geim AK. Publisher Correction: Control of electron-electron interaction in graphene by proximity screening. Nat Commun 2020; 11:3054. [PMID: 32528007 PMCID: PMC7289850 DOI: 10.1038/s41467-020-16708-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- M Kim
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - S G Xu
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - A I Berdyugin
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - A Principi
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - S Slizovskiy
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK.,Saint-Petersburg INP, Gatchina, 188300, Russia
| | - N Xin
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - P Kumaravadivel
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - W Kuang
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - M Hamer
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - R Krishna Kumar
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - R V Gorbachev
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - K Watanabe
- National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - I V Grigorieva
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - V I Fal'ko
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - M Polini
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK. .,Dipartimento di Fisica dell'Università di Pisa, Largo Bruno Pontecorvo 3, 56127, Pisa, Italy. .,Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, 16163, Genova, Italy.
| | - A K Geim
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK. .,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK.
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34
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Calman EV, Fowler-Gerace LH, Choksy DJ, Butov LV, Nikonov DE, Young IA, Hu S, Mishchenko A, Geim AK. Indirect Excitons and Trions in MoSe 2/WSe 2 van der Waals Heterostructures. Nano Lett 2020; 20:1869-1875. [PMID: 32069058 DOI: 10.1021/acs.nanolett.9b05086] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Indirect excitons (IX) in semiconductor heterostructures are bosons, which can cool below the temperature of quantum degeneracy and can be effectively controlled by voltage and light. IX quantum Bose gases and IX devices were explored in GaAs heterostructures where an IX range of existence is limited to low temperatures due to low IX binding energies. IXs in van der Waals transition-metal dichalcogenide (TMD) heterostructures are characterized by large binding energies giving the opportunity for exploring excitonic quantum gases and for creating excitonic devices at high temperatures. TMD heterostructures also offer a new platform for studying single-exciton phenomena and few-particle complexes. In this work, we present studies of IXs in MoSe2/WSe2 heterostructures and report on two IX luminescence lines whose energy splitting and temperature dependence identify them as neutral and charged IXs. The experimentally found binding energy of the indirect charged excitons, that is, indirect trions, is close to the calculated binding energy of 28 meV for negative indirect trions in TMD heterostructures [Deilmann, T.; Thygesen, K. S. Nano Lett. 2018, 18, 1460]. We also report on the realization of IXs with a luminescence line width reaching 4 meV at low temperatures. An enhancement of IX luminescence intensity and the narrow line width are observed in localized spots.
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Affiliation(s)
- E V Calman
- Department of Physics, University of California at San Diego, La Jolla, California 92093, United States
| | - L H Fowler-Gerace
- Department of Physics, University of California at San Diego, La Jolla, California 92093, United States
| | - D J Choksy
- Department of Physics, University of California at San Diego, La Jolla, California 92093, United States
| | - L V Butov
- Department of Physics, University of California at San Diego, La Jolla, California 92093, United States
| | - D E Nikonov
- Components Research, Intel Corporation, Hillsboro, Oregon 97124 United States
| | - I A Young
- Components Research, Intel Corporation, Hillsboro, Oregon 97124 United States
| | - S Hu
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - A Mishchenko
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - A K Geim
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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35
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Velický M, Hu S, Woods CR, Tóth PS, Zólyomi V, Geim AK, Abruña HD, Novoselov KS, Dryfe RAW. Electron Tunneling through Boron Nitride Confirms Marcus-Hush Theory Predictions for Ultramicroelectrodes. ACS Nano 2020; 14:993-1002. [PMID: 31815429 DOI: 10.1021/acsnano.9b08308] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Marcus-Hush theory of electron transfer is one of the pillars of modern electrochemistry with a large body of supporting experimental evidence presented to date. However, some predictions, such as the electrochemical behavior at disk ultramicroelectrodes, remain unverified. Herein, we present a study of electron tunneling across a hexagonal boron nitride acting as a barrier between a graphite electrode and redox mediators in a liquid solution. This was achieved by the fabrication of disk ultramicroelectrodes with a typical diameter of 5 μm. Analysis of voltammetric measurements, using two common outer-sphere redox mediators, yielded several electrochemical parameters, including the electron transfer rate constant, limiting current, and transfer coefficient. They depart significantly from the Butler-Volmer kinetics and instead show behavior previously predicted by the Marcus-Hush theory of electron transfer. In addition, our system provides a noteworthy experimental platform, which could be applied to address a number of scientific problems such as identification of reaction mechanisms, surface modification, or long-range electron transfer.
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Affiliation(s)
- Matěj Velický
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | | | | | - Péter S Tóth
- MTA Premium Post Doctorate Research Program, Department of Physical Chemistry and Materials Science , University of Szeged , Rerrich Square 1 , Szeged H-6720 , Hungary
| | | | | | - Héctor D Abruña
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | - Kostya S Novoselov
- Centre for Advanced 2D Materials , National University of Singapore , 117546 , Singapore
- Chongqing 2D Materials Institute , Liangjiang New Area , Chongqing , 400714 , China
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36
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Yang Y, Zou YC, Woods CR, Shi Y, Yin J, Xu S, Ozdemir S, Taniguchi T, Watanabe K, Geim AK, Novoselov KS, Haigh SJ, Mishchenko A. Stacking Order in Graphite Films Controlled by van der Waals Technology. Nano Lett 2019; 19:8526-8532. [PMID: 31664847 DOI: 10.1021/acs.nanolett.9b03014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In graphite crystals, layers of graphene reside in three equivalent, but distinct, stacking positions typically referred to as A, B, and C projections. The order in which the layers are stacked defines the electronic structure of the crystal, providing an exciting degree of freedom which can be exploited for designing graphitic materials with unusual properties including predicted high-temperature superconductivity and ferromagnetism. However, the lack of control of the stacking sequence limits most research to the stable ABA form of graphite. Here, we demonstrate a strategy to control the stacking order using van der Waals technology. To this end, we first visualize the distribution of stacking domains in graphite films and then perform directional encapsulation of ABC-rich graphite crystallites with hexagonal boron nitride (hBN). We found that hBN encapsulation, which is introduced parallel to the graphite zigzag edges, preserves ABC stacking, while encapsulation along the armchair edges transforms the stacking to ABA. The technique presented here should facilitate new research on the important properties of ABC graphite.
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Affiliation(s)
- Yaping Yang
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
- National Graphene Institute , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
| | - Yi-Chao Zou
- School of Materials , University of Manchester , Manchester M13 9PL , United Kingdom
| | - Colin R Woods
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
- National Graphene Institute , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
| | - Yanmeng Shi
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
- National Graphene Institute , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
| | - Jun Yin
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
| | - Shuigang Xu
- National Graphene Institute , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
| | - Servet Ozdemir
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
| | - Takashi Taniguchi
- National Institute for Materials Science , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Kenji Watanabe
- National Institute for Materials Science , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Andre K Geim
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
- National Graphene Institute , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
| | - Kostya S Novoselov
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
- National Graphene Institute , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
- Centre for Advanced 2D Materials , National University of Singapore , 117546 , Singapore
- Chongqing 2D Materials Institute , Liangjiang New Area , Chongqing 400714 , China
| | - Sarah J Haigh
- School of Materials , University of Manchester , Manchester M13 9PL , United Kingdom
| | - Artem Mishchenko
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
- National Graphene Institute , University of Manchester , Oxford Road , Manchester , M13 9PL , United Kingdom
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37
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Sulpizio JA, Ella L, Rozen A, Birkbeck J, Perello DJ, Dutta D, Ben-Shalom M, Taniguchi T, Watanabe K, Holder T, Queiroz R, Principi A, Stern A, Scaffidi T, Geim AK, Ilani S. Visualizing Poiseuille flow of hydrodynamic electrons. Nature 2019; 576:75-79. [DOI: 10.1038/s41586-019-1788-9] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 10/11/2019] [Indexed: 11/09/2022]
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38
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Mogg L, Hao GP, Zhang S, Bacaksiz C, Zou YC, Haigh SJ, Peeters FM, Geim AK, Lozada-Hidalgo M. Atomically thin micas as proton-conducting membranes. Nat Nanotechnol 2019; 14:962-966. [PMID: 31477802 DOI: 10.1038/s41565-019-0536-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
Monolayers of graphene and hexagonal boron nitride (hBN) are highly permeable to thermal protons1,2. For thicker two-dimensional (2D) materials, proton conductivity diminishes exponentially, so that, for example, monolayer MoS2 that is just three atoms thick is completely impermeable to protons1. This seemed to suggest that only one-atom-thick crystals could be used as proton-conducting membranes. Here, we show that few-layer micas that are rather thick on the atomic scale become excellent proton conductors if native cations are ion-exchanged for protons. Their areal conductivity exceeds that of graphene and hBN by one to two orders of magnitude. Importantly, ion-exchanged 2D micas exhibit this high conductivity inside the infamous gap for proton-conducting materials3, which extends from ∼100 °C to 500 °C. Areal conductivity of proton-exchanged monolayer micas can reach above 100 S cm-2 at 500 °C, well above the current requirements for the industry roadmap4. We attribute the fast proton permeation to ~5-Å-wide tubular channels that perforate micas' crystal structure, which, after ion exchange, contain only hydroxyl groups inside. Our work indicates that there could be other 2D crystals5 with similar nanometre-scale channels, which could help close the materials gap in proton-conducting applications.
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Affiliation(s)
- L Mogg
- National Graphene Institute, The University of Manchester, Manchester, UK
- School of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - G-P Hao
- National Graphene Institute, The University of Manchester, Manchester, UK.
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian, China.
| | - S Zhang
- National Graphene Institute, The University of Manchester, Manchester, UK
- Key Laboratory for Green Chemical Technology of Ministry of Education, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - C Bacaksiz
- Departement Fysica, Universiteit Antwerpen, Antwerp, Belgium
| | - Y-C Zou
- School of Materials, The University of Manchester, Manchester, UK
| | - S J Haigh
- School of Materials, The University of Manchester, Manchester, UK
| | - F M Peeters
- Departement Fysica, Universiteit Antwerpen, Antwerp, Belgium
| | - A K Geim
- National Graphene Institute, The University of Manchester, Manchester, UK.
- School of Physics and Astronomy, The University of Manchester, Manchester, UK.
| | - M Lozada-Hidalgo
- National Graphene Institute, The University of Manchester, Manchester, UK.
- School of Physics and Astronomy, The University of Manchester, Manchester, UK.
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39
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Mogg L, Zhang S, Hao GP, Gopinadhan K, Barry D, Liu BL, Cheng HM, Geim AK, Lozada-Hidalgo M. Perfect proton selectivity in ion transport through two-dimensional crystals. Nat Commun 2019; 10:4243. [PMID: 31534140 PMCID: PMC6751181 DOI: 10.1038/s41467-019-12314-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/23/2019] [Indexed: 11/28/2022] Open
Abstract
Defect-free monolayers of graphene and hexagonal boron nitride are surprisingly permeable to thermal protons, despite being completely impenetrable to all gases. It remains untested whether small ions can permeate through the two-dimensional crystals. Here we show that mechanically exfoliated graphene and hexagonal boron nitride exhibit perfect Nernst selectivity such that only protons can permeate through, with no detectable flow of counterions. In the experiments, we use suspended monolayers that have few, if any, atomic-scale defects, as shown by gas permeation tests, and place them to separate reservoirs filled with hydrochloric acid solutions. Protons account for all the electrical current and chloride ions are blocked. This result corroborates the previous conclusion that thermal protons can pierce defect-free two-dimensional crystals. Besides the importance for theoretical developments, our results are also of interest for research on various separation technologies based on two-dimensional materials. Defect-free monolayers of graphene and hexagonal boron nitride are highly permeable to thermal protons, but are impenetrable to gases. Here the authors show that mechanically exfoliated crystals exhibit perfect proton selectivity, corroborating proton transport through the bulk without atomic-scale defects.
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Affiliation(s)
- L Mogg
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - S Zhang
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK. .,Key Laboratory for Green Chemical Technology of Ministry of Education, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - G-P Hao
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.,State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, China
| | - K Gopinadhan
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.,Department of Physics, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat, 382355, India
| | - D Barry
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - B L Liu
- Shenzhen Graphene Center Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, 1001 Xueyuan Road, Shenzhen, 518055, China
| | - H M Cheng
- Shenzhen Graphene Center Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, 1001 Xueyuan Road, Shenzhen, 518055, China
| | - A K Geim
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK. .,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
| | - M Lozada-Hidalgo
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK. .,Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
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40
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Sreepal V, Yagmurcukardes M, Vasu KS, Kelly DJ, Taylor SFR, Kravets VG, Kudrynskyi Z, Kovalyuk ZD, Patanè A, Grigorenko AN, Haigh SJ, Hardacre C, Eaves L, Sahin H, Geim AK, Peeters FM, Nair RR. Two-Dimensional Covalent Crystals by Chemical Conversion of Thin van der Waals Materials. Nano Lett 2019; 19:6475-6481. [PMID: 31426634 PMCID: PMC6814286 DOI: 10.1021/acs.nanolett.9b02700] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/30/2019] [Indexed: 06/10/2023]
Abstract
Most of the studied two-dimensional (2D) materials have been obtained by exfoliation of van der Waals crystals. Recently, there has been growing interest in fabricating synthetic 2D crystals which have no layered bulk analogues. These efforts have been focused mainly on the surface growth of molecules in high vacuum. Here, we report an approach to making 2D crystals of covalent solids by chemical conversion of van der Waals layers. As an example, we used 2D indium selenide (InSe) obtained by exfoliation and converted it by direct fluorination into indium fluoride (InF3), which has a nonlayered, rhombohedral structure and therefore cannot possibly be obtained by exfoliation. The conversion of InSe into InF3 is found to be feasible for thicknesses down to three layers of InSe, and the obtained stable InF3 layers are doped with selenium. We study this new 2D material by optical, electron transport, and Raman measurements and show that it is a semiconductor with a direct bandgap of 2.2 eV, exhibiting high optical transparency across the visible and infrared spectral ranges. We also demonstrate the scalability of our approach by chemical conversion of large-area, thin InSe laminates obtained by liquid exfoliation, into InF3 films. The concept of chemical conversion of cleavable thin van der Waals crystals into covalently bonded noncleavable ones opens exciting prospects for synthesizing a wide variety of novel atomically thin covalent crystals.
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Affiliation(s)
- Vishnu Sreepal
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Mehmet Yagmurcukardes
- Department
of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
| | - Kalangi S. Vasu
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Daniel J. Kelly
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Sarah F. R. Taylor
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Vasyl G. Kravets
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Zakhar Kudrynskyi
- School of
Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Zakhar D. Kovalyuk
- Institute
for Problems of Materials Science, The National
Academy of Sciences of Ukraine, Chernivtsi Branch, Chernivtsi 58001, Ukraine
| | - Amalia Patanè
- School of
Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Alexander N. Grigorenko
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Sarah J. Haigh
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Christopher Hardacre
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Laurence Eaves
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
- School of
Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Hasan Sahin
- Department
of Photonics, Izmir Institute of Technology, 35430, Izmir, Turkey
| | - Andre K. Geim
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Francois M. Peeters
- Department
of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
| | - Rahul R. Nair
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
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41
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Xu SG, Berdyugin AI, Kumaravadivel P, Guinea F, Krishna Kumar R, Bandurin DA, Morozov SV, Kuang W, Tsim B, Liu S, Edgar JH, Grigorieva IV, Fal'ko VI, Kim M, Geim AK. Giant oscillations in a triangular network of one-dimensional states in marginally twisted graphene. Nat Commun 2019; 10:4008. [PMID: 31488842 PMCID: PMC6728432 DOI: 10.1038/s41467-019-11971-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/12/2019] [Indexed: 11/24/2022] Open
Abstract
At very small twist angles of ∼0.1°, bilayer graphene exhibits a strain-accompanied lattice reconstruction that results in submicron-size triangular domains with the standard, Bernal stacking. If the interlayer bias is applied to open an energy gap inside the domain regions making them insulating, such marginally twisted bilayer graphene is expected to remain conductive due to a triangular network of chiral one-dimensional states hosted by domain boundaries. Here we study electron transport through this helical network and report giant Aharonov-Bohm oscillations that reach in amplitude up to 50% of resistivity and persist to temperatures above 100 K. At liquid helium temperatures, the network exhibits another kind of oscillations that appear as a function of carrier density and are accompanied by a sign-changing Hall effect. The latter are attributed to consecutive population of the narrow minibands formed by the network of one-dimensional states inside the gap. The conductivity of marginally-twisted bilayer graphene is predicted to persist in presence of a bandgap-opening interlayer bias, owing to a network of 1D conductive states at domain boundaries. Here, the authors report Aharonov–Bohm oscillations up to 100 K, whereas at liquid helium temperatures another kind of oscillation appears, due to progressive population of the narrow minibands formed by the 2D network of 1D states inside the gap.
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Affiliation(s)
- S G Xu
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - A I Berdyugin
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - P Kumaravadivel
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - F Guinea
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - R Krishna Kumar
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - D A Bandurin
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - S V Morozov
- Institute of Microelectronics Technology and High Purity Materials, Russian Academy of Sciences, Chernogolovka, 142432, Russia
| | - W Kuang
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - B Tsim
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - S Liu
- The Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, KS, 66506, USA
| | - J H Edgar
- The Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, KS, 66506, USA
| | - I V Grigorieva
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
| | - V I Fal'ko
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - M Kim
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.
| | - A K Geim
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK. .,National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK.
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42
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Nedoliuk IO, Hu S, Geim AK, Kuzmenko AB. Colossal infrared and terahertz magneto-optical activity in a two-dimensional Dirac material. Nat Nanotechnol 2019; 14:756-761. [PMID: 31285609 DOI: 10.1038/s41565-019-0489-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
When two-dimensional electron gases (2DEGs) are exposed to a magnetic field, they resonantly absorb electromagnetic radiation via electronic transitions between Landau levels1. In 2DEGs with a Dirac spectrum, such as graphene, theory predicts an exceptionally high infrared magneto-absorption, even at zero doping2-5. However, the measured Landau-level magneto-optical effects in graphene have been much weaker than expected2,6-12 because of imperfections in the samples available for such experiments. Here, we measure magneto-transmission and Faraday rotation in high-mobility encapsulated monolayer graphene using a custom-designed set-up for magneto-infrared microspectroscopy. Our results show strongly enhanced magneto-optical activity in the infrared and terahertz ranges, characterized by absorption of light near to the 50% maximum allowed, 100% magnetic circular dichroism and high Faraday rotation. Considering that sizeable effects have been already observed at routinely achievable magnetic fields, our findings demonstrate the potential of magnetic tuning in 2D Dirac materials for long-wavelength optoelectronics and plasmonics.
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Affiliation(s)
| | - Sheng Hu
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Andre K Geim
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Alexey B Kuzmenko
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland.
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43
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Ella L, Rozen A, Birkbeck J, Ben-Shalom M, Perello D, Zultak J, Taniguchi T, Watanabe K, Geim AK, Ilani S, Sulpizio JA. Simultaneous voltage and current density imaging of flowing electrons in two dimensions. Nat Nanotechnol 2019; 14:480-487. [PMID: 30858521 DOI: 10.1038/s41565-019-0398-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 01/31/2019] [Indexed: 06/09/2023]
Abstract
A variety of physical phenomena associated with nanoscale electron transport often results in non-trivial spatial voltage and current patterns, particularly in nonlocal transport regimes. While numerous techniques have been devised to image electron flows, the need remains for a nanoscale probe capable of simultaneously imaging current and voltage distributions with high sensitivity and minimal invasiveness, in a magnetic field, across a broad range of temperatures and beneath an insulating surface. Here we present a technique for spatially mapping electron flows based on a nanotube single-electron transistor, which achieves high sensitivity for both voltage and current imaging. In a series of experiments using high-mobility graphene devices, we demonstrate the ability of our technique to visualize local aspects of intrinsically nonlocal transport, as in ballistic flows, which are not easily resolvable via existing methods. This technique should aid in understanding the physics of two-dimensional electronic devices and enable new classes of experiments that image electron flow through buried nanostructures in the quantum and interaction-dominated regimes.
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Affiliation(s)
- Lior Ella
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Asaf Rozen
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - John Birkbeck
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Moshe Ben-Shalom
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
- School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
| | - David Perello
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Johanna Zultak
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | | | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - Andre K Geim
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Shahal Ilani
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Joseph A Sulpizio
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel.
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44
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Berdyugin AI, Xu SG, Pellegrino FMD, Krishna Kumar R, Principi A, Torre I, Ben Shalom M, Taniguchi T, Watanabe K, Grigorieva IV, Polini M, Geim AK, Bandurin DA. Measuring Hall viscosity of graphene's electron fluid. Science 2019; 364:162-165. [PMID: 30819929 DOI: 10.1126/science.aau0685] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 02/19/2019] [Indexed: 01/22/2023]
Abstract
An electrical conductor subjected to a magnetic field exhibits the Hall effect in the presence of current flow. Here, we report a qualitative deviation from the standard behavior in electron systems with high viscosity. We found that the viscous electron fluid in graphene responds to nonquantizing magnetic fields by producing an electric field opposite to that generated by the ordinary Hall effect. The viscous contribution is substantial and identified by studying local voltages that arise in the vicinity of current-injecting contacts. We analyzed the anomaly over a wide range of temperatures and carrier densities and extracted the Hall viscosity, a dissipationless transport coefficient that was long identified theoretically but remained elusive in experiments.
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Affiliation(s)
- A I Berdyugin
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
| | - S G Xu
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - F M D Pellegrino
- Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia, 64, I-95123 Catania, Italy.,Istituto Nazionale di Fisica Nucleare, Sez. Catania, I-95123 Catania, Italy
| | - R Krishna Kumar
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - A Principi
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
| | - I Torre
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - M Ben Shalom
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - T Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan
| | - K Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan
| | - I V Grigorieva
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
| | - M Polini
- Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, 16163 Genova, Italy.,School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
| | - A K Geim
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK. .,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - D A Bandurin
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
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45
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Kim G, Kim SS, Jeon J, Yoon SI, Hong S, Cho YJ, Misra A, Ozdemir S, Yin J, Ghazaryan D, Holwill M, Mishchenko A, Andreeva DV, Kim YJ, Jeong HY, Jang AR, Chung HJ, Geim AK, Novoselov KS, Sohn BH, Shin HS. Author Correction: Planar and van der Waals heterostructures for vertical tunnelling single electron transistors. Nat Commun 2019; 10:987. [PMID: 30804336 PMCID: PMC6389964 DOI: 10.1038/s41467-019-08910-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The original version of this Article contained an error in the spelling of the author Matthew Holwill, which was incorrectly given as Mathew Holwill. This has now been corrected in both the PDF and HTML versions of the Article.
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Affiliation(s)
- Gwangwoo Kim
- Department of Energy Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sung-Soo Kim
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.,Carbon Composite Materials Research Center, Korea Institute of Science and Technology (KIST), Wanju, 55324, Republic of Korea
| | - Jonghyuk Jeon
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seong In Yoon
- Department of Energy Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Seokmo Hong
- Department of Chemistry, UNIST, Ulsan, 44919, Republic of Korea
| | - Young Jin Cho
- Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Abhishek Misra
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom.,Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Servet Ozdemir
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Jun Yin
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Davit Ghazaryan
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom.,Department of Physics, National Research University Higher School of Economics, Staraya Basmannaya 21/4, Moscow, 105066, Russian Federation
| | - Matthew Holwill
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Artem Mishchenko
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Daria V Andreeva
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Yong-Jin Kim
- Center for Multidimensional Carbon Materials, Institute of Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Hu Young Jeong
- UNIST Central Research Facilities (UCRF), UNIST, Ulsan, 44919, Republic of Korea
| | - A-Rang Jang
- Department of Energy Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, 44919, Republic of Korea.,Department of Chemistry, UNIST, Ulsan, 44919, Republic of Korea
| | - Hyun-Jong Chung
- Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Andre K Geim
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Kostya S Novoselov
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom.
| | - Byeong-Hyeok Sohn
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.
| | - Hyeon Suk Shin
- Department of Energy Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, 44919, Republic of Korea. .,Department of Chemistry, UNIST, Ulsan, 44919, Republic of Korea. .,Center for Multidimensional Carbon Materials, Institute of Basic Science (IBS), Ulsan, 44919, Republic of Korea. .,Low Dimensional Carbon Material Center, UNIST, Ulsan, 44919, Republic of Korea.
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46
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Kim G, Kim SS, Jeon J, Yoon SI, Hong S, Cho YJ, Misra A, Ozdemir S, Yin J, Ghazaryan D, Holwill M, Mishchenko A, Andreeva DV, Kim YJ, Jeong HY, Jang AR, Chung HJ, Geim AK, Novoselov KS, Sohn BH, Shin HS. Planar and van der Waals heterostructures for vertical tunnelling single electron transistors. Nat Commun 2019; 10:230. [PMID: 30651554 PMCID: PMC6335417 DOI: 10.1038/s41467-018-08227-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 12/23/2018] [Indexed: 11/09/2022] Open
Abstract
Despite a rich choice of two-dimensional materials, which exists these days, heterostructures, both vertical (van der Waals) and in-plane, offer an unprecedented control over the properties and functionalities of the resulted structures. Thus, planar heterostructures allow p-n junctions between different two-dimensional semiconductors and graphene nanoribbons with well-defined edges; and vertical heterostructures resulted in the observation of superconductivity in purely carbon-based systems and realisation of vertical tunnelling transistors. Here we demonstrate simultaneous use of in-plane and van der Waals heterostructures to build vertical single electron tunnelling transistors. We grow graphene quantum dots inside the matrix of hexagonal boron nitride, which allows a dramatic reduction of the number of localised states along the perimeter of the quantum dots. The use of hexagonal boron nitride tunnel barriers as contacts to the graphene quantum dots make our transistors reproducible and not dependent on the localised states, opening even larger flexibility when designing future devices.
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Affiliation(s)
- Gwangwoo Kim
- Department of Energy Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sung-Soo Kim
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.,Carbon Composite Materials Research Center, Korea Institute of Science and Technology (KIST), Wanju, 55324, Republic of Korea
| | - Jonghyuk Jeon
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seong In Yoon
- Department of Energy Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Seokmo Hong
- Department of Chemistry, UNIST, Ulsan, 44919, Republic of Korea
| | - Young Jin Cho
- Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Abhishek Misra
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom.,Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Servet Ozdemir
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Jun Yin
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Davit Ghazaryan
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom.,Department of Physics, National Research University Higher School of Economics, Staraya Basmannaya 21/4, Moscow, 105066, Russian Federation
| | - Matthew Holwill
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Artem Mishchenko
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Daria V Andreeva
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Yong-Jin Kim
- Center for Multidimensional Carbon Materials, Institute of Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Hu Young Jeong
- UNIST Central Research Facilities (UCRF), UNIST, Ulsan, 44919, Republic of Korea
| | - A-Rang Jang
- Department of Energy Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, 44919, Republic of Korea.,Department of Chemistry, UNIST, Ulsan, 44919, Republic of Korea
| | - Hyun-Jong Chung
- Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Andre K Geim
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Kostya S Novoselov
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom.
| | - Byeong-Hyeok Sohn
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.
| | - Hyeon Suk Shin
- Department of Energy Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, 44919, Republic of Korea. .,Department of Chemistry, UNIST, Ulsan, 44919, Republic of Korea. .,Center for Multidimensional Carbon Materials, Institute of Basic Science (IBS), Ulsan, 44919, Republic of Korea. .,Low Dimensional Carbon Material Center, UNIST, Ulsan, 44919, Republic of Korea.
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47
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Novelli P, Taddei F, Geim AK, Polini M. Failure of Conductance Quantization in Two-Dimensional Topological Insulators due to Nonmagnetic Impurities. Phys Rev Lett 2019; 122:016601. [PMID: 31012652 DOI: 10.1103/physrevlett.122.016601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Indexed: 06/09/2023]
Abstract
Despite topological protection and the absence of magnetic impurities, two-dimensional topological insulators display quantized conductance only in surprisingly short channels, which can be as short as 100 nm for atomically thin materials. We show that the combined action of short-range nonmagnetic impurities located near the edges and on site electron-electron interactions effectively creates noncollinear magnetic scatterers, and, hence, results in strong backscattering. The mechanism causes deviations from quantization even at zero temperature and for a modest strength of electron-electron interactions. Our theory provides a straightforward conceptual framework to explain experimental results, especially those in atomically thin crystals, plagued with short-range edge disorder.
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Affiliation(s)
- Pietro Novelli
- Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, I-16163 Genova, Italy
- NEST, Scuola Normale Superiore, I-56126 Pisa, Italy
| | - Fabio Taddei
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56126 Pisa, Italy
| | - Andre K Geim
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Marco Polini
- Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, I-16163 Genova, Italy
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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48
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Bandurin DA, Svintsov D, Gayduchenko I, Xu SG, Principi A, Moskotin M, Tretyakov I, Yagodkin D, Zhukov S, Taniguchi T, Watanabe K, Grigorieva IV, Polini M, Goltsman GN, Geim AK, Fedorov G. Resonant terahertz detection using graphene plasmons. Nat Commun 2018; 9:5392. [PMID: 30568184 PMCID: PMC6300605 DOI: 10.1038/s41467-018-07848-w] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/26/2018] [Indexed: 11/09/2022] Open
Abstract
Plasmons, collective oscillations of electron systems, can efficiently couple light and electric current, and thus can be used to create sub-wavelength photodetectors, radiation mixers, and on-chip spectrometers. Despite considerable effort, it has proven challenging to implement plasmonic devices operating at terahertz frequencies. The material capable to meet this challenge is graphene as it supports long-lived electrically tunable plasmons. Here we demonstrate plasmon-assisted resonant detection of terahertz radiation by antenna-coupled graphene transistors that act as both plasmonic Fabry-Perot cavities and rectifying elements. By varying the plasmon velocity using gate voltage, we tune our detectors between multiple resonant modes and exploit this functionality to measure plasmon wavelength and lifetime in bilayer graphene as well as to probe collective modes in its moiré minibands. Our devices offer a convenient tool for further plasmonic research that is often exceedingly difficult under non-ambient conditions (e.g. cryogenic temperatures) and promise a viable route for various photonic applications.
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Affiliation(s)
- Denis A Bandurin
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
| | - Dmitry Svintsov
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russian Federation, 141700
| | - Igor Gayduchenko
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russian Federation, 141700
- Physics Department, Moscow State University of Education (MSPU), Moscow, Russian Federation, 119435
| | - Shuigang G Xu
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Alessandro Principi
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Maxim Moskotin
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russian Federation, 141700
- Physics Department, Moscow State University of Education (MSPU), Moscow, Russian Federation, 119435
| | - Ivan Tretyakov
- Physics Department, Moscow State University of Education (MSPU), Moscow, Russian Federation, 119435
| | - Denis Yagodkin
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russian Federation, 141700
- Physics Department, Moscow State University of Education (MSPU), Moscow, Russian Federation, 119435
| | - Sergey Zhukov
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russian Federation, 141700
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Irina V Grigorieva
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Marco Polini
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, 16163, Genova, Italy
| | - Gregory N Goltsman
- Physics Department, Moscow State University of Education (MSPU), Moscow, Russian Federation, 119435
| | - Andre K Geim
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Georgy Fedorov
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russian Federation, 141700.
- Physics Department, Moscow State University of Education (MSPU), Moscow, Russian Federation, 119435.
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49
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Bandurin DA, Shytov AV, Levitov LS, Kumar RK, Berdyugin AI, Ben Shalom M, Grigorieva IV, Geim AK, Falkovich G. Fluidity onset in graphene. Nat Commun 2018; 9:4533. [PMID: 30382090 PMCID: PMC6208423 DOI: 10.1038/s41467-018-07004-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/05/2018] [Indexed: 11/20/2022] Open
Abstract
Viscous electron fluids have emerged recently as a new paradigm of strongly-correlated electron transport in solids. Here we report on a direct observation of the transition to this long-sought-for state of matter in a high-mobility electron system in graphene. Unexpectedly, the electron flow is found to be interaction-dominated but non-hydrodynamic (quasiballistic) in a wide temperature range, showing signatures of viscous flows only at relatively high temperatures. The transition between the two regimes is characterized by a sharp maximum of negative resistance, probed in proximity to the current injector. The resistance decreases as the system goes deeper into the hydrodynamic regime. In a perfect darkness-before-daybreak manner, the interaction-dominated negative response is strongest at the transition to the quasiballistic regime. Our work provides the first demonstration of how the viscous fluid behavior emerges in an interacting electron system.
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Affiliation(s)
- Denis A Bandurin
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Andrey V Shytov
- School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - Leonid S Levitov
- Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA02139, USA
| | - Roshan Krishna Kumar
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Alexey I Berdyugin
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Moshe Ben Shalom
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Irina V Grigorieva
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Andre K Geim
- School of Physics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Gregory Falkovich
- Weizmann Institute of Science, Rehovot, Israel.
- Novosibirsk State University, Novosibirsk, Russia, 630090.
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Fumagalli L, Esfandiar A, Fabregas R, Hu S, Ares P, Janardanan A, Yang Q, Radha B, Taniguchi T, Watanabe K, Gomila G, Novoselov KS, Geim AK. Anomalously low dielectric constant of confined water. Science 2018; 360:1339-1342. [PMID: 29930134 DOI: 10.1126/science.aat4191] [Citation(s) in RCA: 416] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 05/03/2018] [Indexed: 01/02/2023]
Abstract
The dielectric constant ε of interfacial water has been predicted to be smaller than that of bulk water (ε ≈ 80) because the rotational freedom of water dipoles is expected to decrease near surfaces, yet experimental evidence is lacking. We report local capacitance measurements for water confined between two atomically flat walls separated by various distances down to 1 nanometer. Our experiments reveal the presence of an interfacial layer with vanishingly small polarization such that its out-of-plane ε is only ~2. The electrically dead layer is found to be two to three molecules thick. These results provide much-needed feedback for theories describing water-mediated surface interactions and the behavior of interfacial water, and show a way to investigate the dielectric properties of other fluids and solids under extreme confinement.
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Affiliation(s)
- L Fumagalli
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK. .,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - A Esfandiar
- Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran, Iran
| | - R Fabregas
- Departament d'Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, 08028 Barcelona, Spain.,Institut de Bioenginyeria de Catalunya, Barcelona Institute of Science and Technology, C/ Baldiri i Reixac 15-21, 08028 Barcelona, Spain
| | - S Hu
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - P Ares
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - A Janardanan
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Q Yang
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - B Radha
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - T Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - K Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - G Gomila
- Departament d'Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, 08028 Barcelona, Spain.,Institut de Bioenginyeria de Catalunya, Barcelona Institute of Science and Technology, C/ Baldiri i Reixac 15-21, 08028 Barcelona, Spain
| | - K S Novoselov
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - A K Geim
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK. .,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
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