1
|
Zivieri R, Lumetti S, Létang J. High-Mobility Topological Semimetals as Novel Materials for Huge Magnetoresistance Effect and New Type of Quantum Hall Effect. MATERIALS (BASEL, SWITZERLAND) 2023; 16:7579. [PMID: 38138720 PMCID: PMC10744697 DOI: 10.3390/ma16247579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023]
Abstract
The quantitative description of electrical and magnetotransport properties of solid-state materials has been a remarkable challenge in materials science over recent decades. Recently, the discovery of a novel class of materials-the topological semimetals-has led to a growing interest in the full understanding of their magnetotransport properties. In this review, the strong interplay among topology, band structure, and carrier mobility in recently discovered high carrier mobility topological semimetals is discussed and their effect on their magnetotransport properties is outlined. Their large magnetoresistance effect, especially in the Hall transverse configuration, and a new version of a three-dimensional quantum Hall effect observed in high-mobility Weyl and Dirac semimetals are reviewed. The possibility of designing novel quantum sensors and devices based on solid-state semimetals is also examined.
Collapse
Affiliation(s)
| | | | - Jérémy Létang
- Silicon Austria Labs, 9524 Villach, Austria; (S.L.); (J.L.)
| |
Collapse
|
2
|
Xie Y, Wang C, Fei F, Li Y, Xing Q, Huang S, Lei Y, Zhang J, Mu L, Dai Y, Song F, Yan H. Tunable optical topological transitions of plasmon polaritons in WTe 2 van der Waals films. LIGHT, SCIENCE & APPLICATIONS 2023; 12:193. [PMID: 37553359 PMCID: PMC10409815 DOI: 10.1038/s41377-023-01244-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 07/20/2023] [Accepted: 07/23/2023] [Indexed: 08/10/2023]
Abstract
Naturally existing in-plane hyperbolic polaritons and the associated optical topological transitions, which avoid the nano-structuring to achieve hyperbolicity, can outperform their counterparts in artificial metasurfaces. Such plasmon polaritons are rare, but experimentally revealed recently in WTe2 van der Waals thin films. Different from phonon polaritons, hyperbolic plasmon polaritons originate from the interplay of free carrier Drude response and interband transitions, which promise good intrinsic tunability. However, tunable in-plane hyperbolic plasmon polariton and its optical topological transition of the isofrequency contours to the elliptic topology in a natural material have not been realized. Here we demonstrate the tuning of the optical topological transition through Mo doping and temperature. The optical topological transition energy is tuned over a wide range, with frequencies ranging from 429 cm-1 (23.3 microns) for pure WTe2 to 270 cm-1 (37.0 microns) at the 50% Mo-doping level at 10 K. Moreover, the temperature-induced blueshift of the optical topological transition energy is also revealed, enabling active and reversible tuning. Surprisingly, the localized surface plasmon resonance in skew ribbons shows unusual polarization dependence, accurately manifesting its topology, which renders a reliable means to track the topology with far-field techniques. Our results open an avenue for reconfigurable photonic devices capable of plasmon polariton steering, such as canaling, focusing, and routing, and pave the way for low-symmetry plasmonic nanophotonics based on anisotropic natural materials.
Collapse
Affiliation(s)
- Yuangang Xie
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Chong Wang
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, 100081, Beijing, China.
- Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081, Beijing, China.
| | - Fucong Fei
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, 210093, Nanjing, China.
- Atom Manufacturing Institute (AMI), 211805, Nanjing, China.
| | - Yuqi Li
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, 100081, Beijing, China
- Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081, Beijing, China
| | - Qiaoxia Xing
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Shenyang Huang
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Yuchen Lei
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Jiasheng Zhang
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Lei Mu
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Yaomin Dai
- Center for Superconducting Physics and Materials, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, 211805, Nanjing, China
| | - Fengqi Song
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, 210093, Nanjing, China
- Atom Manufacturing Institute (AMI), 211805, Nanjing, China
| | - Hugen Yan
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), and Department of Physics, Fudan University, 200433, Shanghai, China.
| |
Collapse
|
3
|
Giwa R, Hosur P. Superconductor Vortex Spectrum Including Fermi Arc States in Time-Reversal Symmetric Weyl Semimetals. PHYSICAL REVIEW LETTERS 2023; 130:156402. [PMID: 37115867 DOI: 10.1103/physrevlett.130.156402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 12/21/2022] [Accepted: 03/27/2023] [Indexed: 06/19/2023]
Abstract
Using semiclassics to surmount the hurdle of bulk-surface inseparability, we derive the superconductor vortex spectrum in nonmagnetic Weyl semimetals and show that it stems from the Berry phase of orbits made of Fermi arcs on opposite surfaces and bulk chiral modes. Tilting the vortex transmutes it between bosonic, fermionic, and supersymmetric, produces periodic peaks in the density of states that signify novel nonlocal Majorana modes, and yields a thickness-independent spectrum at magic "magic angles." We propose (Nb,Ta)P as candidate materials and tunneling spectroscopy as the ideal experiment.
Collapse
Affiliation(s)
- Rauf Giwa
- University of Houston, Houston, Texas 77204, USA
| | - Pavan Hosur
- University of Houston, Houston, Texas 77204, USA
- Texas Center for Superconductivity at the University of Houston, Houston, Texas 77204, USA
| |
Collapse
|
4
|
Sun W, Chen Y, Zhuang W, Chen Z, Song A, Liu R, Wang X. Sizable spin-to-charge conversion in PLD-grown amorphous (Mo, W)Te 2-xfilms. NANOTECHNOLOGY 2023; 34:135001. [PMID: 36584386 DOI: 10.1088/1361-6528/acaf34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
We report on the spin-to-charge conversion (SCC) in Mo0.25W0.75Te2-x(MWT)/Y3Fe5O12(YIG) heterostructures at room temperature. The centimeter-scale amorphous MWT films are deposited on liquid-phase-epitaxial YIG by pulsed laser deposition technique. The significant SCC voltage is measured in the MWT layer with a sizable spin Hall angle of ∼0.021 by spin pumping experiments. The control experiments by inserting MgO or Ag layer between MWT and YIG show that the SCC is mainly attributed to the inverse spin Hall effect rather than the thermal or interfacial Rashba effect. Our work provides a novel spin-source material for energy-efficient topological spintronic devices.
Collapse
Affiliation(s)
- Wenxuan Sun
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Yequan Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Wenzhuo Zhuang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Zhongqiang Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Anke Song
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Ruxin Liu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Xuefeng Wang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| |
Collapse
|
5
|
Cho S, Huh S, Fang Y, Hua C, Bai H, Jiang Z, Liu Z, Liu J, Chen Z, Fukushima Y, Harasawa A, Kawaguchi K, Shin S, Kondo T, Lu Y, Mu G, Huang F, Shen D. Direct Observation of the Topological Surface State in the Topological Superconductor 2M-WS 2. NANO LETTERS 2022; 22:8827-8834. [PMID: 36367457 DOI: 10.1021/acs.nanolett.2c02372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The quantum spin Hall (QSH) effect has attracted extensive research interest because of the potential applications in spintronics and quantum computing, which is attributable to two conducting edge channels with opposite spin polarization and the quantized electronic conductance of 2e2/h. Recently, 2M-WS2, a new stable phase of transition metal dichalcogenides with a 2M structure showing a layer configuration identical to that of the monolayer 1T' TMDs, was suggested to be a QSH insulator as well as a superconductor with a critical transition temperature of around 8 K. Here, high-resolution angle-resolved photoemission spectroscopy (ARPES) and spin-resolved ARPES are applied to investigate the electronic and spin structure of the topological surface states (TSS) in the superconducting 2M-WS2. The TSS exhibit characteristic spin-momentum-locking behavior, suggesting the existence of long-sought nontrivial Z2 topological states therein. We expect that 2M-WS2 with coexisting superconductivity and TSS might host the promising Majorana bound states.
Collapse
Affiliation(s)
- Soohyun Cho
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai200050, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing100049, People's Republic of China
| | - Soonsang Huh
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba277-8581, Japan
| | - Yuqiang Fang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai200050, People's Republic of China
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, People's Republic of China
| | - Chenqiang Hua
- Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou310027, People's Republic of China
| | - Hua Bai
- Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou310027, People's Republic of China
| | - Zhicheng Jiang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai200050, People's Republic of China
| | - Zhengtai Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai200050, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing100049, People's Republic of China
| | - Jishan Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai200050, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing100049, People's Republic of China
| | - Zhenhua Chen
- Shanghai Synchrotron Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai201204, People's Republic of China
| | - Yuto Fukushima
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba277-8581, Japan
| | - Ayumi Harasawa
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba277-8581, Japan
| | - Kaishu Kawaguchi
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba277-8581, Japan
| | - Shik Shin
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba277-8581, Japan
| | - Takeshi Kondo
- Trans-Scale Quantum Science Institute, The University of Tokyo, Bunkyo-ku, Tokyo113-0033, Japan
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba277-8581, Japan
| | - Yunhao Lu
- Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou310027, People's Republic of China
| | - Gang Mu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai200050, People's Republic of China
| | - Fuqiang Huang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai200050, People's Republic of China
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, People's Republic of China
| | - Dawei Shen
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai200050, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing100049, People's Republic of China
| |
Collapse
|
6
|
Zhang G, Wu H, Zhang L, Yang L, Xie Y, Guo F, Li H, Tao B, Wang G, Zhang W, Chang H. Two-Dimensional Van Der Waals Topological Materials: Preparation, Properties, and Device Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2204380. [PMID: 36135779 DOI: 10.1002/smll.202204380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/23/2022] [Indexed: 06/16/2023]
Abstract
Over the past decade, 2D van der Waals (vdW) topological materials (TMs), including topological insulators and topological semimetals, which combine atomically flat 2D layers and topologically nontrivial band structures, have attracted increasing attention in condensed-matter physics and materials science. These easily cleavable and integrated TMs provide the ideal platform for exploring topological physics in the 2D limit, where new physical phenomena may emerge, and represent a potential to control and investigate exotic properties and device applications in nanoscale topological phases. However, multifaced efforts are still necessary, which is the prerequisite for the practical application of 2D vdW TMs. Herein, this review focuses on the preparation, properties, and device applications of 2D vdW TMs. First, three common preparation strategies for 2D vdW TMs are summarized, including single crystal exfoliation, chemical vapor deposition, and molecular beam epitaxy. Second, the origin and regulation of various properties of 2D vdW TMs are introduced, involving electronic properties, transport properties, optoelectronic properties, thermoelectricity, ferroelectricity, and magnetism. Third, some device applications of 2D vdW TMs are presented, including field-effect transistors, memories, spintronic devices, and photodetectors. Finally, some significant challenges and opportunities for the practical application of 2D vdW TMs in 2D topological electronics are briefly addressed.
Collapse
Affiliation(s)
- Gaojie Zhang
- Quantum-Nano Matter and Device Lab, Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hao Wu
- Quantum-Nano Matter and Device Lab, Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Liang Zhang
- Liuzhou Key Laboratory for New Energy Vehicle Power Lithium Battery, School of Microelectronics and Engineering, Guangxi University of Science and Technology, Liuzhou, 545006, China
| | - Li Yang
- Quantum-Nano Matter and Device Lab, Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yuanmiao Xie
- Liuzhou Key Laboratory for New Energy Vehicle Power Lithium Battery, School of Microelectronics and Engineering, Guangxi University of Science and Technology, Liuzhou, 545006, China
| | - Fei Guo
- Liuzhou Key Laboratory for New Energy Vehicle Power Lithium Battery, School of Microelectronics and Engineering, Guangxi University of Science and Technology, Liuzhou, 545006, China
| | - Hongda Li
- Liuzhou Key Laboratory for New Energy Vehicle Power Lithium Battery, School of Microelectronics and Engineering, Guangxi University of Science and Technology, Liuzhou, 545006, China
| | - Boran Tao
- Liuzhou Key Laboratory for New Energy Vehicle Power Lithium Battery, School of Microelectronics and Engineering, Guangxi University of Science and Technology, Liuzhou, 545006, China
| | - Guofu Wang
- Liuzhou Key Laboratory for New Energy Vehicle Power Lithium Battery, School of Microelectronics and Engineering, Guangxi University of Science and Technology, Liuzhou, 545006, China
| | - Wenfeng Zhang
- Quantum-Nano Matter and Device Lab, Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Shenzhen R&D Center of Huazhong University of Science and Technology (HUST), Shenzhen, 518000, China
| | - Haixin Chang
- Quantum-Nano Matter and Device Lab, Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Shenzhen R&D Center of Huazhong University of Science and Technology (HUST), Shenzhen, 518000, China
| |
Collapse
|
7
|
Roy S, Narayan A. Non-linear Hall effect in multi-Weyl semimetals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:385301. [PMID: 35820408 DOI: 10.1088/1361-648x/ac8091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
In the presence of time reversal symmetry, a non-linear Hall effect can occur in systems without an inversion symmetry. One of the prominent candidates for detection of such Hall signals are Weyl semimetals. In this article, we investigate the Berry curvature induced second and third order Hall effect in multi-Weyl semimetals with topological chargesn=1,2,3. We use low energy effective models to obtain general analytical expressions and discover the presence of a large Berry curvature dipole (BCD) in multi-Weyl semimetals, compared to usual (n = 1) Weyl semimetals. We also study the BCD in a realistic tight-binding lattice model and observe two different kinds of variation with increasing topological charge-these can be attributed to different underlying Berry curvature components. We provide estimates of the signatures of second harmonic of Hall signal in multi-Weyl semimetals, which can be detected experimentally. Furthermore, we predict the existence of a third order Hall signal in multi-Weyl semimetals. We derive the analytical expressions of Berry connection polarizability tensor, which is responsible for third order effects, using a low energy model and estimate the measurable conductivity. Our work can help guide experimental discovery of Berry curvature multipole physics in multi-Weyl semimetals.
Collapse
Affiliation(s)
- Saswata Roy
- Undergraduate Programme, Indian Institute of Science, Bangalore 560012, India
| | - Awadhesh Narayan
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
8
|
Vergniory MG, Wieder BJ, Elcoro L, Parkin SSP, Felser C, Bernevig BA, Regnault N. All topological bands of all nonmagnetic stoichiometric materials. Science 2022; 376:eabg9094. [PMID: 35587971 DOI: 10.1126/science.abg9094] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Topological quantum chemistry and symmetry-based indicators have facilitated large-scale searches for materials with topological properties at the Fermi energy (EF). We report the implementation of a publicly accessible catalog of stable and fragile topology in all of the bands both at and away from EF in the 96,196 processable entries in the Inorganic Crystal Structure Database. Our calculations, which represent the completion of the symmetry-indicated band topology of known nonmagnetic materials, have enabled the discovery of repeat-topological and supertopological materials, including rhombohedral bismuth and Bi2Mg3. We find that 52.65% of all materials are topological at EF, roughly two-thirds of bands across all materials exhibit symmetry-indicated stable topology, and 87.99% of all materials contain at least one stable or fragile topological band.
Collapse
Affiliation(s)
- Maia G Vergniory
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain.,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Benjamin J Wieder
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Physics, Northeastern University, Boston, MA 02115, USA.,Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Luis Elcoro
- Department of Condensed Matter Physics, University of the Basque Country UPV/EHU, 48080 Bilbao, Spain
| | - Stuart S P Parkin
- Max Planck Institute of Microstructure Physics, 06120 Halle, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - B Andrei Bernevig
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Nicolas Regnault
- Department of Physics, Princeton University, Princeton, NJ 08544, USA.,Laboratoire de Physique de l'École Normale Supérieure, PSL University, CNRS, Sorbonne Université, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| |
Collapse
|
9
|
Deng Y, Li P, Zhu C, Zhou J, Wang X, Cui J, Yang X, Tao L, Zeng Q, Duan R, Fu Q, Zhu C, Xu J, Qu F, Yang C, Jing X, Lu L, Liu G, Liu Z. Controlled Synthesis of Mo xW 1-xTe 2 Atomic Layers with Emergent Quantum States. ACS NANO 2021; 15:11526-11534. [PMID: 34162202 DOI: 10.1021/acsnano.1c01441] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recently, new states of matter like superconducting or topological quantum states were found in transition metal dichalcogenides (TMDs) and manifested themselves in a series of exotic physical behaviors. Such phenomena have been demonstrated to exist in a series of transition metal tellurides including MoTe2, WTe2, and alloyed MoxW1-xTe2. However, the behaviors in the alloy system have been rarely addressed due to their difficulty in obtaining atomic layers with controlled composition, albeit the alloy offers a great platform to tune the quantum states. Here, we report a facile CVD method to synthesize the MoxW1-xTe2 with controllable thickness and chemical composition ratios. The atomic structure of a monolayer MoxW1-xTe2 alloy was experimentally confirmed by scanning transmission electron microscopy. Importantly, two different transport behaviors including superconducting and Weyl semimetal states were observed in Mo-rich Mo0.8W0.2Te2 and W-rich Mo0.2W0.8Te2 samples, respectively. Our results show that the electrical properties of MoxW1-xTe2 can be tuned by controlling the chemical composition, demonstrating our controllable CVD growth method is an efficient strategy to manipulate the physical properties of TMDCs. Meanwhile, it provides a perspective on further comprehension and sheds light on the design of devices with topological multicomponent TMDC materials.
Collapse
Affiliation(s)
- Ya Deng
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Peiling Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao Zhu
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Jiadong Zhou
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Xiaowei Wang
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Jian Cui
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xue Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Tao
- Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Qingsheng Zeng
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Ruihuan Duan
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Qundong Fu
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Chao Zhu
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Jianbin Xu
- Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Fanming Qu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Changli Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiunian Jing
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Li Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Guangtong Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Zheng Liu
- CINTRA CNRS/NTU/THALES, UMI 3288, Singapore 637553, Singapore
- School of Materials Science and Engineering, School of Physical and Mathematical Science and School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
| |
Collapse
|
10
|
He Y, Wang TL, Zhang M, Wang TW, Wu LF, Zeng L, Wang X, Boubeche M, Wang S, Yan K, Lin SH, Luo H. Discovery and Facile Synthesis of a New Silicon Based Family as Efficient Hydrogen Evolution Reaction Catalysts: A Computational and Experimental Investigation of Metal Monosilicides. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006153. [PMID: 33512059 DOI: 10.1002/smll.202006153] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/17/2020] [Indexed: 06/12/2023]
Abstract
A new family of transition-metal monosilicides (MSi, M = Ti, Mn, Fe, Ru, Ni, Pd, Co, and Rh) electrocatalysts with superior electrocatalytic performance of hydrogen evolution is reported, based on the computational and experimental results. It is proposed that these MSi can be synthesized within several minutes by adopting the arc-melting method. The previously reported RuSi is not only fabricated more readily but eventually explored 8 MSi that can be good hydrogen evolution reaction catalysts. Silicides then can be another promising electrocatalysts family as carbides, wherein carbon has the same electronic configuration as silicon. All explored silicides electrodes exhibited low overpotentials (34-54 mV at 10 mA cm-2 ) with Tafel slopes from 23.6 to 32.3 mV dec-1 , which are comparable to that of the commercial 20 wt% Pt/C (37 mV, 26.1 mV dec-1 ). First-principles calculations demonstrated that the superior performance can be attributed to the high catalytic reactivity per site that can even function at high hydrogen coverages (≈100%) on multiple low surface energy facets. The work sheds light on a new class of electrocatalysts for hydrogen evolution, with earth-abundant and inexpensive silicon-based compounds.
Collapse
Affiliation(s)
- Yuan He
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Key Lab of Polymer Composite & Functional Materials, Sun Yat-Sen University, No.135, Xingang Xi Road, Guangzhou, 510275, P. R. China
| | - Tan-Ling Wang
- Department of Materials and Optoelectronic Science & Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan
| | - Man Zhang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Ta-Wei Wang
- Department of Materials and Optoelectronic Science & Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan
| | - Li-Fan Wu
- Department of Materials and Optoelectronic Science & Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan
| | - Lingyong Zeng
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Key Lab of Polymer Composite & Functional Materials, Sun Yat-Sen University, No.135, Xingang Xi Road, Guangzhou, 510275, P. R. China
| | - Xiaopeng Wang
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Key Lab of Polymer Composite & Functional Materials, Sun Yat-Sen University, No.135, Xingang Xi Road, Guangzhou, 510275, P. R. China
| | - Mebrouka Boubeche
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Key Lab of Polymer Composite & Functional Materials, Sun Yat-Sen University, No.135, Xingang Xi Road, Guangzhou, 510275, P. R. China
| | - Shu Wang
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Key Lab of Polymer Composite & Functional Materials, Sun Yat-Sen University, No.135, Xingang Xi Road, Guangzhou, 510275, P. R. China
| | - Kai Yan
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Shi-Hsin Lin
- Department of Materials and Optoelectronic Science & Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan
| | - Huixia Luo
- School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Key Lab of Polymer Composite & Functional Materials, Sun Yat-Sen University, No.135, Xingang Xi Road, Guangzhou, 510275, P. R. China
| |
Collapse
|
11
|
Wiscons RA, Cho Y, Han SY, Dismukes AH, Meirzadeh E, Nuckolls C, Berkelbach TC, Roy X. Polytypism, Anisotropic Transport, and Weyl Nodes in the van der Waals Metal TaFeTe4. J Am Chem Soc 2020; 143:109-113. [DOI: 10.1021/jacs.0c11674] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Ren A. Wiscons
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Yeongsu Cho
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Sae Young Han
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Avalon H. Dismukes
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Elena Meirzadeh
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Timothy C. Berkelbach
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Xavier Roy
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| |
Collapse
|
12
|
Mortelmans W, Nalin Mehta A, Balaji Y, Sergeant S, Meng R, Houssa M, De Gendt S, Heyns M, Merckling C. On the van der Waals Epitaxy of Homo-/Heterostructures of Transition Metal Dichalcogenides. ACS APPLIED MATERIALS & INTERFACES 2020; 12:27508-27517. [PMID: 32447952 DOI: 10.1021/acsami.0c05872] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Layered materials held together by weak van der Waals (vdW) interactions are a promising class of materials in the field of nanotechnology. Besides the potential for single layers, stacking of various vdW layers becomes even more promising since unique properties can hence be precisely engineered. The synthesis of stacked vdW layers, however, remains to date, hardly understood. Therefore, in this work, the vdW epitaxy of transition metal dichalcogenides (TMDs) on single-crystalline TMD templates is investigated in depth. It is demonstrated that the role of lattice mismatch is insignificant. More importantly is the role of surface energy, calculated using density functional theory, which plays an essential role in the activation energy for adatom diffusion, hence nucleation density. This in turn correlates with defect density since the stacking sequence in vdW epitaxy is generally poorly controlled. Moreover, the vapor pressure of the transition metal is also found to correlate with adatom diffusion. Consequently, the proposed study enables important and new insight in the vdW epitaxy of multilayer 2D homo-/heterostructures.
Collapse
Affiliation(s)
- Wouter Mortelmans
- Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, 3001 Leuven, Belgium
- Imec, Kapeldreef 75, 3001 Leuven, Belgium
| | - Ankit Nalin Mehta
- Imec, Kapeldreef 75, 3001 Leuven, Belgium
- Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, 3001 Leuven, Belgium
| | - Yashwanth Balaji
- Imec, Kapeldreef 75, 3001 Leuven, Belgium
- Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, 3001 Leuven, Belgium
| | | | - Ruishen Meng
- Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, 3001 Leuven, Belgium
| | - Michel Houssa
- Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, 3001 Leuven, Belgium
| | - Stefan De Gendt
- Imec, Kapeldreef 75, 3001 Leuven, Belgium
- Department of Chemistry, KU Leuven, Celestijnenlaan 200f, 3001 Leuven, Belgium
| | - Marc Heyns
- Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, 3001 Leuven, Belgium
- Imec, Kapeldreef 75, 3001 Leuven, Belgium
| | | |
Collapse
|
13
|
Lin CL, Kawakami N, Arafune R, Minamitani E, Takagi N. Scanning tunneling spectroscopy studies of topological materials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:243001. [PMID: 32069440 DOI: 10.1088/1361-648x/ab777d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Topological materials have become promising materials for next-generation devices by utilizing their exotic electronic states. Their exotic states caused by spin-orbital coupling usually locate on the surfaces or at the edges. Scanning tunneling spectroscopy (STS) is a powerful tool to reveal the local electronic structures of condensed matters. Therefore, STS provides us with an almost perfect method to access the exotic states of topological materials. In this topical review, we report the current investigations by several methods based on the STS technique for layered topological material from transition metal dichalcogenide Weyl semimetals (WTe2 and MoTe2) to two dimensional topological insulators (layered bismuth and silicene). The electronic characteristics of these layered topological materials are experimentally identified.
Collapse
Affiliation(s)
- Chun-Liang Lin
- Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | | | | | | | | |
Collapse
|
14
|
Wang Z, Zhao X, Yang Y, Qiao L, Lv L, Chen Z, Di Z, Ren W, Pennycook SJ, Zhou J, Gao Y. Phase-Controlled Synthesis of Monolayer W 1- x Re x S 2 Alloy with Improved Photoresponse Performance. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2000852. [PMID: 32323489 DOI: 10.1002/smll.202000852] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/20/2020] [Accepted: 03/21/2020] [Indexed: 06/11/2023]
Abstract
Tuning bandgap and phases in the ternary 2D transition metal dichalcogenides (TMDs) alloys has opened up unexpected opportunities to engineer optoelectronic properties and explore potential applications. In this work, a salt-assisted chemical deposition vapor (CVD) growth strategy is reported for the creation of high-quality monolayer W1- x Rex S2 alloys to fulfill a readily phase control from 1H to DT by changing the ratio of Re and W precursors. The structures and chemical compositions of doping alloys are confirmed by combining atomic resolution scanning transmission electron microscopy-annular dark field imaging with energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy, matching well with the calculated results. The field-effect transistors (FETs) devices fabricated based on 1H-W0.9 Re0.1 S2 monolayer exhibit a n-type semiconducting behavior with the mobility of 0.4 cm2 V-1 s-1 . More importantly, the FETs show high-performance responsivity with a value of 17 µA W-1 in air, which is superior to that of monolayer CVD-grown WS2 . This work paves the way toward synthesizing monolayer ternary alloys with controlled phases for potential optoelectronic applications.
Collapse
Affiliation(s)
- Zixuan Wang
- School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China
| | - Xiaoxu Zhao
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117575, Singapore
| | - Yuekun Yang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
| | - Lei Qiao
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, MGI and ICQMS, Shanghai University, Shanghai, 200444, China
| | - Lu Lv
- School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China
| | - Zhang Chen
- School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China
| | - Zengfeng Di
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
| | - Wei Ren
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, MGI and ICQMS, Shanghai University, Shanghai, 200444, China
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117575, Singapore
| | - Jiadong Zhou
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Yanfeng Gao
- School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China
| |
Collapse
|
15
|
Wang AQ, Ye XG, Yu DP, Liao ZM. Topological Semimetal Nanostructures: From Properties to Topotronics. ACS NANO 2020; 14:3755-3778. [PMID: 32286783 DOI: 10.1021/acsnano.9b07990] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Characterized by bulk Dirac or Weyl cones and surface Fermi-arc states, topological semimetals have sparked enormous research interest in recent years. The nanostructures, with large surface-to-volume ratio and easy field-effect gating, provide ideal platforms to detect and manipulate the topological quantum states. Exotic physical properties originating from these topological states endow topological semimetals attractive for future topological electronics (topotronics). For example, the linear energy dispersion relation is promising for broadband infrared photodetectors, the spin-momentum locking nature of topological surface states is valuable for spintronics, and the topological superconductivity is highly desirable for fault-tolerant qubits. For real-life applications, topological semimetals in the form of nanostructures are necessary in terms of convenient fabrication and integration. Here, we review the recent progresses in topological semimetal nanostructures and start with the quantum transport properties. Then topological semimetal-based electronic devices are introduced. Finally, we discuss several important aspects that should receive great effort in the future, including controllable synthesis, manipulation of quantum states, topological field effect transistors, spintronic applications, and topological quantum computation.
Collapse
Affiliation(s)
- An-Qi Wang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Xing-Guo Ye
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Da-Peng Yu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhi-Min Liao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China
| |
Collapse
|
16
|
Yan D, Wang S, Lin Y, Wang G, Zeng Y, Boubeche M, He Y, Ma J, Wang Y, Yao DX, Luo H. NbSeTe-a new layered transition metal dichalcogenide superconductor. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:025702. [PMID: 31546238 DOI: 10.1088/1361-648x/ab46d0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Transition metal dichalcogenides (TMDCs) usually exhibit layered polytypic structures due to the weak interlayer coupling. 2H-NbSe2 is one of the most widely studied in the pristine TMDC family due to its high superconducting transition temperature (T c = 7.3 K) and the occurrence of a charge-density wave (CDW) order below 33 K. The coexistence of CDW with superconductivity poses an intriguing open question about the relationship between Fermi surface nesting and Cooper pairing. Past studies of this issue have mostly been focused on doping 2H-NbSe2 by 3d transition metals without significantly changing its crystal structure. Here we replaced the Se by Te in 2H-NbSe2 in order to design a new 1T polytype layered TMDC NbSeTe, which adopts a trigonal structure with space group P [Formula: see text] m1. We successfully grew large size and high-quality single crystals of 1T-NbSeTe via the vapor transport method using I 2 as the transport agent. Temperature-dependent resistivity and specific heat data revealed a bulk T c at 1.3 K, which is the first observation of superconductivity in pure 1T-NbSeTe phase. This compound enlarged the family of superconducting TMDCs and provides an opportunity to study the interplay between CDW and superconductivity in the trigonal structure.
Collapse
Affiliation(s)
- Dong Yan
- School of Material Science and Engineering and Key Lab of Polymer Composite & Functional Materials, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Mortelmans W, El Kazzi S, Nalin Mehta A, Vanhaeren D, Conard T, Meersschaut J, Nuytten T, De Gendt S, Heyns M, Merckling C. Peculiar alignment and strain of 2D WSe 2 grown by van der Waals epitaxy on reconstructed sapphire surfaces. NANOTECHNOLOGY 2019; 30:465601. [PMID: 31426041 DOI: 10.1088/1361-6528/ab3c9b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The increasing scientific and industry interest in 2D MX2 materials within the field of nanotechnology has made the single crystalline integration of large area van der Waals (vdW) layers on commercial substrates an important topic. The c-plane oriented (3D crystal) sapphire surface is believed to be an interesting substrate candidate for this challenging 2D/3D integration. Despite the many attempts that have been made, the yet incomplete understanding of vdW epitaxy still results in synthetic material that shows a crystallinity far too low compared to natural crystals that can be exfoliated onto commercial substrates. Thanks to its atomic control and in situ analysis possibilities, molecular beam epitaxy (MBE) offers a potential solution and an appropriate method to enable a more in-depth understanding of this peculiar 2D/3D hetero-epitaxy. Here, we report on how various sapphire surface reconstructions, that are obtained by thermal annealing of the as-received substrates, influence the vdW epitaxy of the MBE-grown WSe2 monolayers (MLs). The surface chemistry and the interatomic arrangement of the reconstructed sapphire surfaces are shown to control the preferential in-plane epitaxial alignment of the stoichiometric WSe2 crystals. In addition, it is demonstrated that the reconstructions also affect the in-plane lattice parameter and thus the in-plane strain of the 2D vdW-bonded MLs. Hence, the results obtained in this work shine more light on the peculiar concept of vdW epitaxy, especially relevant for 2D materials integration on large-scale 3D crystal commercial substrates.
Collapse
Affiliation(s)
- Wouter Mortelmans
- KU Leuven, Department of Materials Engineering, Kasteelpark Arenberg 44, B-3001, Leuven, Belgium. Imec, Kapeldreef 75, B-3001, Leuven, Belgium
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Abstract
The discovery of topological insulators and semimetals has opened up a new perspective to understand materials. Owing to the special band structure and enlarged Berry curvature, the linear responses are strongly enhanced in topological materials. The interplay of topological band structure and symmetries plays a crucial role for designing new materials with strong and exotic new electromagnetic responses and provides promising mechanisms and new materials for the next generation of technological applications. We review the fundamental concept of linear responses in topological materials from the symmetry point of view and discuss their potential applications.
Collapse
|
19
|
von Rohr FO, Orain JC, Khasanov R, Witteveen C, Shermadini Z, Nikitin A, Chang J, Wieteska AR, Pasupathy AN, Hasan MZ, Amato A, Luetkens H, Uemura YJ, Guguchia Z. Unconventional scaling of the superfluid density with the critical temperature in transition metal dichalcogenides. SCIENCE ADVANCES 2019; 5:eaav8465. [PMID: 31819897 PMCID: PMC6884407 DOI: 10.1126/sciadv.aav8465] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
We report on muon spin rotation experiments probing the magnetic penetration depth λ(T) in the layered superconductors in 2H-NbSe2 and 4H-NbSe2. The current results, along with our earlier findings on 1T'-MoTe2 (Guguchia et al.), demonstrate that the superfluid density scales linearly with T c in the three transition metal dichalcogenide superconductors. Upon increasing pressure, we observe a substantial increase of the superfluid density in 2H-NbSe2, which we find to correlate with T c. The correlation deviates from the abovementioned linear trend. A similar deviation from the Uemura line was also observed in previous pressure studies of optimally doped cuprates. This correlation between the superfluid density and T c is considered a hallmark feature of unconventional superconductivity. Here, we show that this correlation is an intrinsic property of the superconductivity in transition metal dichalcogenides, whereas the ratio T c/T F is approximately a factor of 20 lower than the ratio observed in hole-doped cuprates. We, furthermore, find that the values of the superconducting gaps are insensitive to the suppression of the charge density wave state.
Collapse
Affiliation(s)
- F. O. von Rohr
- Department of Chemistry, University of Zürich, CH-8057 Zürich, Switzerland
- Physik-Institut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - J.-C. Orain
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - R. Khasanov
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - C. Witteveen
- Department of Chemistry, University of Zürich, CH-8057 Zürich, Switzerland
| | - Z. Shermadini
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - A. Nikitin
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - J. Chang
- Physik-Institut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - A. R. Wieteska
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - A. N. Pasupathy
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - M. Z. Hasan
- Laboratory for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - A. Amato
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - H. Luetkens
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Y. J. Uemura
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - Z. Guguchia
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- Department of Physics, Columbia University, New York, NY 10027, USA
- Laboratory for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University, Princeton, NJ 08544, USA
| |
Collapse
|
20
|
Zhang Y, Yao Y, Sendeku MG, Yin L, Zhan X, Wang F, Wang Z, He J. Recent Progress in CVD Growth of 2D Transition Metal Dichalcogenides and Related Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1901694. [PMID: 31402526 DOI: 10.1002/adma.201901694] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/20/2019] [Indexed: 06/10/2023]
Abstract
In recent years, 2D layered materials have received considerable research interest on account of their substantial material systems and unique physicochemical properties. Among them, 2D layered transition metal dichalcogenides (TMDs), a star family member, have already been explored over the last few years and have exhibited excellent performance in electronics, catalysis, and other related fields. However, to fulfill the requirement for practical application, the batch production of 2D TMDs is essential. Recently, the chemical vapor deposition (CVD) technique was considered as an elegant alternative for successfully growing 2D TMDs and their heterostructures. The latest research advances in the controllable synthesis of 2D TMDs and related heterostructures/superlattices via the CVD approach are illustrated here. The controlled growth behavior, preparation strategies, and breakthroughs on the synthesis of new 2D TMDs and their heterostructures, as well as their unique physical phenomena, are also discussed. Recent progress on the application of CVD-grown 2D materials is revealed with particular attention to electronics/optoelectronic devices and catalysts. Finally, the challenges and future prospects are considered regarding the current development of 2D TMDs and related heterostructures.
Collapse
Affiliation(s)
- Yu Zhang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yuyu Yao
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- Sino-Danish College, University of Chinese Academy of Science, Beijing, 100049, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing, 100049, China
| | - Marshet Getaye Sendeku
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing, 100049, China
| | - Lei Yin
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing, 100049, China
| | - Xueying Zhan
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Feng Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Zhenxing Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Jun He
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| |
Collapse
|
21
|
Ji Z, Liu G, Addison Z, Liu W, Yu P, Gao H, Liu Z, Rappe AM, Kane CL, Mele EJ, Agarwal R. Spatially dispersive circular photogalvanic effect in a Weyl semimetal. NATURE MATERIALS 2019; 18:955-962. [PMID: 31308515 DOI: 10.1038/s41563-019-0421-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 06/04/2019] [Indexed: 06/10/2023]
Abstract
Weyl semimetals (WSMs) are gapless topological states of matter with broken inversion and/or time reversal symmetry. WSMs can support a circulating photocurrent when illuminated by circularly polarized light at normal incidence. Here, we report a spatially dispersive circular photogalvanic effect (s-CPGE) in a WSM that occurs with a spatially varying beam profile. Our analysis shows that the s-CPGE is controlled by a symmetry selection rule combined with asymmetric carrier excitation and relaxation dynamics. By evaluating the s-CPGE for a minimal model of a WSM, a frequency-dependent scaling behaviour of the photocurrent is obtained. Wavelength-dependent measurements from the visible to mid-infrared range show evidence of Berry curvature singularities and band inversion in the s-CPGE response. We present the s-CPGE as a promising spectroscopic probe for topological band properties, with the potential for controlling photoresponse by patterning optical fields on topological materials to store, manipulate and transmit information.
Collapse
Affiliation(s)
- Zhurun Ji
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Gerui Liu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Zachariah Addison
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Wenjing Liu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Peng Yu
- Centre for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Heng Gao
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Zheng Liu
- Centre for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Andrew M Rappe
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Charles L Kane
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Eugene J Mele
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Ritesh Agarwal
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
22
|
Xia H, Li Y, Cai M, Qin L, Zou N, Peng L, Duan W, Xu Y, Zhang W, Fu YS. Dimensional Crossover and Topological Phase Transition in Dirac Semimetal Na 3Bi Films. ACS NANO 2019; 13:9647-9654. [PMID: 31398000 DOI: 10.1021/acsnano.9b04933] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Three-dimensional (3D) topological Dirac semimetal, when thinned down to 2D few layers, is expected to possess gapped Dirac nodes via quantum confinement effect and concomitantly display the intriguing quantum spin Hall (QSH) insulator phase. However, the 3D-to-2D crossover and the associated topological phase transition, which is valuable for understanding the topological quantum phases, remain unexplored. Here, we synthesize high-quality Na3Bi thin films with √3 × √3 reconstruction on graphene and systematically characterize their thickness-dependent electronic and topological properties by scanning tunneling microscopy/spectroscopy in combination with first-principles calculations. We demonstrate that Dirac gaps emerge in Na3Bi films, providing spectroscopic evidence of dimensional crossover from a 3D semimetal to a 2D topological insulator. Importantly, the Dirac gaps are revealed to be of sizable magnitudes on three and four monolayers (72 and 65 meV, respectively) with topologically nontrivial edge states. Moreover, the Fermi energy of a Na3Bi film can be tuned via a certain growth process, thus offering a viable way for achieving charge neutrality in transport. The feasibility of controlling Dirac gap opening and charge neutrality enables realizing intrinsic high-temperature QSH effect in Na3Bi films and achieving potential applications in topological devices.
Collapse
Affiliation(s)
- Huinan Xia
- School of Physics and Wuhan National High Magnetic Field Center , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Yang Li
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics , Tsinghua University , Beijing 100084 , China
- Collaborative Innovation Center of Quantum Matter , Tsinghua University , Beijing 100084 , China
- RIKEN Center for Emergent Matter Science (CEMS) , Wako , Saitama 351-0198 , Japan
| | - Min Cai
- School of Physics and Wuhan National High Magnetic Field Center , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Le Qin
- School of Physics and Wuhan National High Magnetic Field Center , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Nianlong Zou
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics , Tsinghua University , Beijing 100084 , China
- Collaborative Innovation Center of Quantum Matter , Tsinghua University , Beijing 100084 , China
- RIKEN Center for Emergent Matter Science (CEMS) , Wako , Saitama 351-0198 , Japan
| | - Lang Peng
- School of Physics and Wuhan National High Magnetic Field Center , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Wenhui Duan
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics , Tsinghua University , Beijing 100084 , China
- Collaborative Innovation Center of Quantum Matter , Tsinghua University , Beijing 100084 , China
- Institute for Advanced Study , Tsinghua University , Beijing 100084 , China
| | - Yong Xu
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics , Tsinghua University , Beijing 100084 , China
- Collaborative Innovation Center of Quantum Matter , Tsinghua University , Beijing 100084 , China
- RIKEN Center for Emergent Matter Science (CEMS) , Wako , Saitama 351-0198 , Japan
| | - Wenhao Zhang
- School of Physics and Wuhan National High Magnetic Field Center , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Ying-Shuang Fu
- School of Physics and Wuhan National High Magnetic Field Center , Huazhong University of Science and Technology , Wuhan 430074 , China
| |
Collapse
|
23
|
Fang Y, Pan J, Zhang D, Wang D, Hirose HT, Terashima T, Uji S, Yuan Y, Li W, Tian Z, Xue J, Ma Y, Zhao W, Xue Q, Mu G, Zhang H, Huang F. Discovery of Superconductivity in 2M WS 2 with Possible Topological Surface States. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1901942. [PMID: 31157482 DOI: 10.1002/adma.201901942] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/12/2019] [Indexed: 06/09/2023]
Abstract
Recently the metastable 1T'-type VIB-group transition metal dichalcogenides (TMDs) have attracted extensive attention due to their rich and intriguing physical properties, including superconductivity, valleytronics physics, and topological physics. Here, a new layered WS2 dubbed "2M" WS2 , is constructed from 1T' WS2 monolayers, is synthesized. Its phase is defined as 2M based on the number of layers in each unit cell and the subordinate crystallographic system. Intrinsic superconductivity is observed in 2M WS2 with a transition temperature Tc of 8.8 K, which is the highest among TMDs not subject to any fine-tuning process. Furthermore, the electronic structure of 2M WS2 is found by Shubnikov-de Haas oscillations and first-principles calculations to have a strong anisotropy. In addition, topological surface states with a single Dirac cone, protected by topological invariant Z2 , are predicted through first-principles calculations. These findings reveal that the new 2M WS2 might be an interesting topological superconductor candidate from the VIB-group transition metal dichalcogenides.
Collapse
Affiliation(s)
- Yuqiang Fang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, 200050, P. R. China
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Jie Pan
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, 200050, P. R. China
| | - Dongqin Zhang
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, P. R. China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, P. R. China
| | - Dong Wang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, 200050, P. R. China
| | - Hishiro T Hirose
- National Institute for Materials Science, Tsukuba, Ibaraki, 305-0003, Japan
| | - Taichi Terashima
- National Institute for Materials Science, Tsukuba, Ibaraki, 305-0003, Japan
| | - Shinya Uji
- National Institute for Materials Science, Tsukuba, Ibaraki, 305-0003, Japan
| | - Yonghao Yuan
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, 100084, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100084, P. R. China
| | - Wei Li
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, 100084, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100084, P. R. China
| | - Zhen Tian
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, P. R. China
| | - Jiamin Xue
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, P. R. China
| | - Yonghui Ma
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, P. R. China
| | - Wei Zhao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, 200050, P. R. China
| | - Qikun Xue
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, 100084, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100084, P. R. China
| | - Gang Mu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, P. R. China
| | - Haijun Zhang
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, P. R. China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, P. R. China
| | - Fuqiang Huang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, 200050, P. R. China
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
| |
Collapse
|
24
|
Yao MY, Xu N, Wu QS, Autès G, Kumar N, Strocov VN, Plumb NC, Radovic M, Yazyev OV, Felser C, Mesot J, Shi M. Observation of Weyl Nodes in Robust Type-II Weyl Semimetal WP_{2}. PHYSICAL REVIEW LETTERS 2019; 122:176402. [PMID: 31107063 DOI: 10.1103/physrevlett.122.176402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Indexed: 06/09/2023]
Abstract
Distinct to type-I Weyl semimetals (WSMs) that host quasiparticles described by the Weyl equation, the energy dispersion of quasiparticles in type-II WSMs violates Lorentz invariance and the Weyl cones in the momentum space are tilted. Since it was proposed that type-II Weyl fermions could emerge from (W,Mo)Te_{2} and (W,Mo)P_{2} families of materials, a large number of experiments have been dedicated to unveiling the possible manifestation of type-II WSMs, e.g., surface-state Fermi arcs. However, the interpretations of the experimental results are very controversial. Here, using angle-resolved photoemission spectroscopy supported by the first-principles calculations, we probe the tilted Weyl cone bands in the bulk electronic structure of WP_{2} directly, which are at the origin of Fermi arcs at the surfaces and transport properties related to the chiral anomaly in type-II WSMs. Our results ascertain that, due to the spin-orbit coupling, the Weyl nodes originate from the splitting of fourfold degenerate band-crossing points with Chern numbers C=±2 induced by the crystal symmetries of WP_{2}, which is unique among all the discovered WSMs. Our finding also provides a guiding line to observe the chiral anomaly that could manifest in novel transport properties.
Collapse
Affiliation(s)
- M-Y Yao
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - N Xu
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Institute of Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Q S Wu
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials MARVEL, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - G Autès
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials MARVEL, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - N Kumar
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - V N Strocov
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - M Radovic
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - O V Yazyev
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials MARVEL, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - C Felser
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - J Mesot
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Laboratory for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| |
Collapse
|
25
|
Baumbach R, Balicas L, McCandless GT, Sotelo P, Zhang QR, Evans J, Camdzic D, Martin TJ, Chan JY, Macaluso RT. One-dimensional tellurium chains: Crystal structure and thermodynamic properties of PrCuxTe2 (x ~ 0.45). J SOLID STATE CHEM 2019. [DOI: 10.1016/j.jssc.2018.10.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
26
|
Da Y, Liu J, Zhou L, Zhu X, Chen X, Fu L. Engineering 2D Architectures toward High-Performance Micro-Supercapacitors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1802793. [PMID: 30133023 DOI: 10.1002/adma.201802793] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 06/11/2018] [Indexed: 05/23/2023]
Abstract
The rise of micro-supercapacitors is satisfying the demand for power storage in portable devices and wireless gadgets. But the miniaturization of the energy-storage components is significantly limited by their energy density. Electrode materials with adequate electrochemical active surfaces are therefore required for improving performance. 2D materials with ultralarge specific surface areas offer a broad portfolio of the development of high-performance micro-supercapacitors in spite of their several critical drawbacks. An architecture engineering strategy is therefore developed to break these natural limits and maximize the significant advantages of these materials. Based on the approaches of phase transformation, intercalation, surface modification, material hybridization, and hierarchical structuration, 2D architectures with improved conductivity, enlarged specific surface, enhanced redox activity, as well as the unique synergetic effect exhibit great promise in the application of miniaturized supercapacitors with highly enhanced performance. Herein, the architecture engineering of emerging 2D materials beyond graphene toward optimizing the performance of micro-supercapacitors is discussed, in order to promote the application of 2D architectures in miniaturized energy-storage devices.
Collapse
Affiliation(s)
- Yumin Da
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Jinxin Liu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Lu Zhou
- Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Xiaohui Zhu
- Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Xiaodong Chen
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Lei Fu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
- Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| |
Collapse
|
27
|
Buchhold M, Diehl S, Altland A. Vanishing Density of States in Weakly Disordered Weyl Semimetals. PHYSICAL REVIEW LETTERS 2018; 121:215301. [PMID: 30517815 DOI: 10.1103/physrevlett.121.215301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Indexed: 06/09/2023]
Abstract
The Brillouin zone of the clean Weyl semimetal contains points at which the density of states (DOS) vanishes. Previous work suggested that below a certain critical concentration of impurities this feature is preserved including in the presence of disorder. This result got criticized for its neglect of rare disorder fluctuations which might bind quantum states and hence generate a finite DOS. We here show that in spite of their existence these states are so fragile that their contribution effectively vanishes when averaged over continuous disorder distributions. This means that the integrity of the nodal points remains protected for weak disorder.
Collapse
Affiliation(s)
- Michael Buchhold
- Department of Physics and Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - Sebastian Diehl
- Institute for Theoretical Physics, Universität zu Köln, D-509237 Köln, Germany
| | - Alexander Altland
- Institute for Theoretical Physics, Universität zu Köln, D-509237 Köln, Germany
| |
Collapse
|
28
|
Weber AP, Rüßmann P, Xu N, Muff S, Fanciulli M, Magrez A, Bugnon P, Berger H, Plumb NC, Shi M, Blügel S, Mavropoulos P, Dil JH. Spin-Resolved Electronic Response to the Phase Transition in MoTe_{2}. PHYSICAL REVIEW LETTERS 2018; 121:156401. [PMID: 30362784 DOI: 10.1103/physrevlett.121.156401] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 06/27/2018] [Indexed: 06/08/2023]
Abstract
The semimetal MoTe_{2} is studied by spin- and angle-resolved photoemission spectroscopy across the centrosymmetry-breaking structural transition temperature of the bulk. A three-dimensional spin-texture is observed in the bulk Fermi surface in the low temperature, noncentrosymmetric phase that is consistent with first-principles calculations. The spin texture and two types of surface Fermi arc are not completely suppressed above the bulk transition temperature. The lifetimes of quasiparticles forming the Fermi arcs depend on thermal history and lengthen considerably upon cooling toward the bulk structural transition. The results indicate that a new form of polar instability exists near the surface when the bulk is largely in a centrosymmetric phase.
Collapse
Affiliation(s)
- Andrew P Weber
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
- Donostia International Physics Center, 20018 Donostia, Gipuzkoa, Spain
| | - Philipp Rüßmann
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - Nan Xu
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Stefan Muff
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Mauro Fanciulli
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Arnaud Magrez
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Philippe Bugnon
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Helmuth Berger
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Nicholas C Plumb
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Ming Shi
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Stefan Blügel
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - Phivos Mavropoulos
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
- Department of Physics, National and Kapodistrian University of Athens, 15784 Zografou, Greece
| | - J Hugo Dil
- Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| |
Collapse
|
29
|
Alisultanov ZZ. The induced by an electromagnetic field coexistence of types I and II spectra in Weyl semimetals. Sci Rep 2018; 8:13707. [PMID: 30209410 PMCID: PMC6135849 DOI: 10.1038/s41598-018-32104-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 09/03/2018] [Indexed: 11/24/2022] Open
Abstract
Due to their unique properties, Weyl semimetals (WSMs) are promising materials for the future electronics. Currently, the two types (I and II) of WSMs are discovered experimentally. These types of WSMs differ from each other in their topological properties. In this paper we showed that a coexistence of types I and II Weyls spectra is possible in some WSMs under crossed magnetic and electric fields. This is possible in systems with non-equivalent Weyl points (WPs). In particular, it is possible in strained WSMs. Such phase, controlled by electromagnetic field, is principally new for topological matter physics. It is obvious, that in this regime new features of electron transport will appear. We showed that this effect can also be considered as a mechanism of strain induced type-I-type-II transition.
Collapse
Affiliation(s)
- Zaur Z Alisultanov
- Amirkhanov Institute of Physics, Russian Academy of Sciences, Dagestan Science Centre, Makhachkala, Russia. .,Dagestan State University, Makhachkala, Russia.
| |
Collapse
|
30
|
Fei F, Bo X, Wang P, Ying J, Li J, Chen K, Dai Q, Chen B, Sun Z, Zhang M, Qu F, Zhang Y, Wang Q, Wang X, Cao L, Bu H, Song F, Wan X, Wang B. Band Structure Perfection and Superconductivity in Type-II Dirac Semimetal Ir 1-x Pt x Te 2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801556. [PMID: 30019415 DOI: 10.1002/adma.201801556] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 06/13/2018] [Indexed: 06/08/2023]
Abstract
The discovery of a new type-II Dirac semimetal in Ir1-x Ptx Te2 with optimized band structure is described. Pt dopants protect the crystal structure holding the Dirac cones and tune the Fermi level close to the Dirac point. The type-II Dirac dispersion in Ir1-x Ptx Te2 is confirmed by angle-resolved photoemission spectroscopy and first-principles calculations. Superconductivity is also observed and persists when the Fermi level aligns with the Dirac points. Ir1-x Ptx Te2 is an ideal platform for further studies on the exotic properties and potential applications of type-II DSMs, and opens up a new route for the investigation of the possible topological superconductivity and Majorana physics.
Collapse
Affiliation(s)
- Fucong Fei
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Xiangyan Bo
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Pengdong Wang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, China
| | - Jianghua Ying
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jian Li
- Westlake Institute for Advanced Study, Hangzhou, 310012, China
| | - Ke Chen
- Nanophotonics Research Division, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Qing Dai
- Nanophotonics Research Division, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Bo Chen
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Zhe Sun
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, China
| | - Minhao Zhang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Fanming Qu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yi Zhang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Qianghua Wang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Xuefeng Wang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Lu Cao
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Haijun Bu
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Fengqi Song
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Xiangang Wan
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| | - Baigeng Wang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Department of Physics, Nanjing University, Nanjing, 210093, China
| |
Collapse
|
31
|
Singh B, Chang G, Chang TR, Huang SM, Su C, Lin MC, Lin H, Bansil A. Tunable double-Weyl Fermion semimetal state in the SrSi 2 materials class. Sci Rep 2018; 8:10540. [PMID: 30002388 PMCID: PMC6043586 DOI: 10.1038/s41598-018-28644-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 06/20/2018] [Indexed: 11/13/2022] Open
Abstract
We discuss first-principles topological electronic structure of noncentrosymmetric SrSi2 materials class based on the hybrid exchange-correlation functional. Topological phase diagram of SrSi2 is mapped out as a function of the lattice constant with focus on the semimetal order. A tunable double-Weyl Fermion state in Sr1-xCaxSi2 and Sr1-xBaxSi2 alloys is identified. Ca doping in SrSi2 is shown to yield a double-Weyl semimetal with a large Fermi arc length, while Ba doping leads to a transition from the topological semimetal to a gapped insulator state. Our study indicates that SrSi2 materials family could provide an interesting platform for accessing the unique topological properties of Weyl semimetals.
Collapse
Affiliation(s)
- Bahadur Singh
- SZU-NUS Collaborative Center and International Collaborative Laboratory of 2D Materials for Optoelectronic Science & Technology, Engineering Technology Research Center for 2D Materials Information Functional Devices and Systems of Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, ShenZhen, 518060, China
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore, 117546, Singapore
| | - Guoqing Chang
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore, 117546, Singapore
- Department of Physics, National University of Singapore, Singapore, 117546, Singapore
- Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan
| | - Tay-Rong Chang
- Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan
| | - Shin-Ming Huang
- Department of Physics, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Chenliang Su
- SZU-NUS Collaborative Center and International Collaborative Laboratory of 2D Materials for Optoelectronic Science & Technology, Engineering Technology Research Center for 2D Materials Information Functional Devices and Systems of Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, ShenZhen, 518060, China.
| | - Ming-Chieh Lin
- Multidisciplinary Computational Laboratory, Department of Electrical and Biomedical Engineering, Hanyang University, Seoul, 04763, South Korea.
| | - Hsin Lin
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore, 117546, Singapore.
- Department of Physics, National University of Singapore, Singapore, 117546, Singapore.
- Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan.
| | - Arun Bansil
- Department of Physics, Northeastern University, Boston, Massachusetts, 02115, USA
| |
Collapse
|
32
|
Han GH, Duong DL, Keum DH, Yun SJ, Lee YH. van der Waals Metallic Transition Metal Dichalcogenides. Chem Rev 2018; 118:6297-6336. [PMID: 29957928 DOI: 10.1021/acs.chemrev.7b00618] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Transition metal dichalcogenides are layered materials which are composed of transition metals and chalcogens of the group VIA in a 1:2 ratio. These layered materials have been extensively investigated over synthesis and optical and electrical properties for several decades. It can be insulators, semiconductors, or metals revealing all types of condensed matter properties from a magnetic lattice distorted to superconducting characteristics. Some of these also feature the topological manner. Instead of covering the semiconducting properties of transition metal dichalcogenides, which have been extensively revisited and reviewed elsewhere, here we present the structures of metallic transition metal dichalcogenides and their synthetic approaches for not only high-quality wafer-scale samples using conventional methods (e.g., chemical vapor transport, chemical vapor deposition) but also local small areas by a modification of the materials using Li intercalation, electron beam irradiation, light illumination, pressures, and strains. Some representative band structures of metallic transition metal dichalcogenides and their strong layer-dependence are reviewed and updated, both in theoretical calculations and experiments. In addition, we discuss the physical properties of metallic transition metal dichalcogenides such as periodic lattice distortion, magnetoresistance, superconductivity, topological insulator, and Weyl semimetal. Approaches to overcome current challenges related to these materials are also proposed.
Collapse
Affiliation(s)
- Gang Hee Han
- Center for Integrated Nanostructure Physics (CINAP) , Institute for Basic Science (IBS) , Suwon 16419 , Republic of Korea.,Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Dinh Loc Duong
- Center for Integrated Nanostructure Physics (CINAP) , Institute for Basic Science (IBS) , Suwon 16419 , Republic of Korea.,Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Dong Hoon Keum
- Center for Integrated Nanostructure Physics (CINAP) , Institute for Basic Science (IBS) , Suwon 16419 , Republic of Korea.,Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Seok Joon Yun
- Center for Integrated Nanostructure Physics (CINAP) , Institute for Basic Science (IBS) , Suwon 16419 , Republic of Korea.,Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP) , Institute for Basic Science (IBS) , Suwon 16419 , Republic of Korea.,Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea.,Department of Physics , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| |
Collapse
|
33
|
Liu Y, Gu Q, Peng Y, Qi S, Zhang N, Zhang Y, Ma X, Zhu R, Tong L, Feng J, Liu Z, Chen JH. Raman Signatures of Broken Inversion Symmetry and In-Plane Anisotropy in Type-II Weyl Semimetal Candidate TaIrTe 4. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1706402. [PMID: 29736942 DOI: 10.1002/adma.201706402] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 02/10/2018] [Indexed: 06/08/2023]
Abstract
The layered ternary compound TaIrTe4 is an important candidate to host the recently predicted type-II Weyl fermions. However, a direct and definitive proof of the absence of inversion symmetry in this material, a prerequisite for the existence of Weyl Fermions, has so far remained evasive. Herein, an unambiguous identification of the broken inversion symmetry in TaIrTe4 is established using angle-resolved polarized Raman spectroscopy. Combining with high-resolution transmission electron microscopy, an efficient and nondestructive recipe to determine the exact crystallographic orientation of TaIrTe4 crystals is demonstrated. Such technique could be extended to the fast identification and characterization of other type-II Weyl fermions candidates. A surprisingly strong in-plane electrical anisotropy in TaIrTe4 thin flakes is also revealed, up to 200% at 10 K, which is the strongest known electrical anisotropy for materials with comparable carrier density, notably in such good metals as copper and silver.
Collapse
Affiliation(s)
- Yinan Liu
- International Center for Quantum Materials, School of Physics, Peking University, No. 5 Yiheyuan Road, Beijing, 100871, China
| | - Qiangqiang Gu
- International Center for Quantum Materials, School of Physics, Peking University, No. 5 Yiheyuan Road, Beijing, 100871, China
| | - Yu Peng
- Centre for Programmed Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Shaomian Qi
- International Center for Quantum Materials, School of Physics, Peking University, No. 5 Yiheyuan Road, Beijing, 100871, China
| | - Na Zhang
- College of Chemistry and Molecular Engineering, Peking University, No. 5 Yiheyuan Road, Beijing, 100871, China
| | - Yinong Zhang
- International Center for Quantum Materials, School of Physics, Peking University, No. 5 Yiheyuan Road, Beijing, 100871, China
| | - Xiumei Ma
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871, China
| | - Rui Zhu
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871, China
| | - Lianming Tong
- College of Chemistry and Molecular Engineering, Peking University, No. 5 Yiheyuan Road, Beijing, 100871, China
| | - Ji Feng
- International Center for Quantum Materials, School of Physics, Peking University, No. 5 Yiheyuan Road, Beijing, 100871, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China
| | - Zheng Liu
- Centre for Programmed Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Jian-Hao Chen
- International Center for Quantum Materials, School of Physics, Peking University, No. 5 Yiheyuan Road, Beijing, 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China
| |
Collapse
|
34
|
Wang Q, Li J, Besbas J, Hsu C, Cai K, Yang L, Cheng S, Wu Y, Zhang W, Wang K, Chang T, Lin H, Chang H, Yang H. Room-Temperature Nanoseconds Spin Relaxation in WTe 2 and MoTe 2 Thin Films. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1700912. [PMID: 29938171 PMCID: PMC6010885 DOI: 10.1002/advs.201700912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 02/28/2018] [Indexed: 06/08/2023]
Abstract
The Weyl semimetal WTe2 and MoTe2 show great potential in generating large spin currents since they possess topologically protected spin-polarized states and can carry a very large current density. In addition, the intrinsic non-centrosymmetry of WTe2 and MoTe2 endows with a unique property of crystal symmetry-controlled spin-orbit torques. An important question to be answered for developing spintronic devices is how spins relax in WTe2 and MoTe2. Here, a room-temperature spin relaxation time of 1.2 ns (0.4 ns) in WTe2 (MoTe2) thin film using the time-resolved Kerr rotation (TRKR) is reported. Based on ab initio calculation, a mechanism of long-lived spin polarization resulting from a large spin splitting around the bottom of the conduction band, low electron-hole recombination rate, and suppression of backscattering required by time-reversal and lattice symmetry operation is identified. In addition, it is found that the spin polarization is firmly pinned along the strong internal out-of-plane magnetic field induced by large spin splitting. This work provides an insight into the physical origin of long-lived spin polarization in Weyl semimetals, which could be useful to manipulate spins for a long time at room temperature.
Collapse
Affiliation(s)
- Qisheng Wang
- Department of Electrical and Computer Engineering, and NUSNNINational University of SingaporeSingapore117576Singapore
| | - Jie Li
- Center for Joining and Electronic PackagingState Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China
| | - Jean Besbas
- Department of Electrical and Computer Engineering, and NUSNNINational University of SingaporeSingapore117576Singapore
| | - Chuang‐Han Hsu
- Department of PhysicsNational University of Singapore2 Science Drive 3Singapore117542Singapore
- Centre for Advanced 2D Materials and Graphene Research CentreNational University of Singapore6 Science Drive 2Singapore117546Singapore
| | - Kaiming Cai
- SKLSMInstitute of SemiconductorsChinese Academy of SciencesP. O. Box 912Beijing100083China
| | - Li Yang
- Center for Joining and Electronic PackagingState Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China
| | - Shuai Cheng
- Center for Joining and Electronic PackagingState Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China
| | - Yang Wu
- Department of Electrical and Computer Engineering, and NUSNNINational University of SingaporeSingapore117576Singapore
| | - Wenfeng Zhang
- Center for Joining and Electronic PackagingState Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China
| | - Kaiyou Wang
- SKLSMInstitute of SemiconductorsChinese Academy of SciencesP. O. Box 912Beijing100083China
| | - Tay‐Rong Chang
- Department of PhysicsNational Cheng Kung UniversityTainan701Taiwan
| | - Hsin Lin
- Department of PhysicsNational University of Singapore2 Science Drive 3Singapore117542Singapore
- Centre for Advanced 2D Materials and Graphene Research CentreNational University of Singapore6 Science Drive 2Singapore117546Singapore
- Institute of PhysicsAcademia SinicaTaipei11529Taiwan
| | - Haixin Chang
- Center for Joining and Electronic PackagingState Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, and NUSNNINational University of SingaporeSingapore117576Singapore
| |
Collapse
|
35
|
Fu D, Pan X, Bai Z, Fei F, Umana-Membreno GA, Song H, Wang X, Wang B, Song F. Tuning the electrical transport of type II Weyl semimetal WTe 2 nanodevices by Mo doping. NANOTECHNOLOGY 2018; 29:135705. [PMID: 29432212 DOI: 10.1088/1361-6528/aaa811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We fabricated nanodevices from MoxW1-xTe2 (x = 0, 0.07, 0.35), and conducted a systematic comparative study of their electrical transport. Magnetoresistance measurements show that Mo doping can significantly suppress mobility and magnetoresistance. The results for the analysis of the two band model show that doping with Mo does not break the carrier balance. Through analysis of Shubnikov-de Haas oscillations, we found that Mo doping also has a strong suppressive effect on the quantum oscillation of the sample, and the higher the ratio of Mo, the fewer pockets were observed in our experiments. Furthermore, the effective mass of electron and hole increases gradually with increasing Mo ratio, while the corresponding quantum mobility decreases rapidly.
Collapse
Affiliation(s)
- Dongzhi Fu
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing, 210093, People's Republic of China
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Huang H, Jin KH, Liu F. Alloy Engineering of Topological Semimetal Phase Transition in MgTa_{2-x}Nb_{x}N_{3}. PHYSICAL REVIEW LETTERS 2018; 120:136403. [PMID: 29694185 DOI: 10.1103/physrevlett.120.136403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Indexed: 06/08/2023]
Abstract
Dirac, triple-point, and Weyl fermions represent three topological semimetal phases, characterized with a descending degree of band degeneracy, which have been realized separately in specific crystalline materials with different lattice symmetries. Here we demonstrate an alloy engineering approach to realize all three types of fermions in one single material system of MgTa_{2-x}Nb_{x}N_{3}. Based on symmetry analysis and first-principles calculations, we map out a phase diagram of topological order in the parameter space of alloy concentration and crystalline symmetry, where the intrinsic MgTa_{2}N_{3} with the highest symmetry hosts the Dirac semimetal phase, which transforms into the triple-point and then the Weyl semimetal phases with increasing Nb concentration that lowers the crystalline symmetries. Therefore, alloy engineering affords a unique approach for the experimental investigation of topological transitions of semimetallic phases manifesting different fermionic behaviors.
Collapse
Affiliation(s)
- Huaqing Huang
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA
| | - Kyung-Hwan Jin
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA
| | - Feng Liu
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| |
Collapse
|
37
|
Jiang L, Feng L, Yao H, Zheng Y. Electronic transport property in Weyl semimetal with local Weyl cone tilt. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:115001. [PMID: 29419521 DOI: 10.1088/1361-648x/aaade4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In realistic materials of Weyl semimetal (WSM), the Weyl cone tilt (WCT) is allowed due to the absence of Lorentz invariance in condensed matter physics. In this context, we theoretically study the electronic transport property in WSM with the local WCT as the scattering mechanism. In so doing, we establish an electronic transport structure of WSM with the WCT occurring only in the central region sandwiched between two pieces of semi-infinite WSM without the WCT. By means of two complementary theoretical approaches, i.e. the continuum-model method and the lattice-model method, the electronic transmission probability, the conductivity and the Fano factor as functions of the incident electron energy are calculated respectively. We find that the WCT can give rise to nontrivial intervalley scattering, as a result, the Klein tunneling is notably suppressed. More importantly, the minimal conductivity of a WSM shifts in energy from the Weyl nodal point. The Fano factor of the shot noise deviates obviously from the sub-Poissonian value in a two dimensional WSM with the WCT.
Collapse
Affiliation(s)
- Liwei Jiang
- Key Laboratory of Physics and Technology for Advanced Batteries(Ministry of Education), College of Physics, Jilin University, Changchun 130012, People's Republic of China
| | | | | | | |
Collapse
|
38
|
Cui F, Feng Q, Hong J, Wang R, Bai Y, Li X, Liu D, Zhou Y, Liang X, He X, Zhang Z, Liu S, Lei Z, Liu Z, Zhai T, Xu H. Synthesis of Large-Size 1T' ReS 2x Se 2(1-x) Alloy Monolayer with Tunable Bandgap and Carrier Type. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1705015. [PMID: 29058350 DOI: 10.1002/adma.201705015] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Indexed: 06/07/2023]
Abstract
Chemical vapor deposition growth of 1T' ReS2x Se2(1-x) alloy monolayers is reported for the first time. The composition and the corresponding bandgap of the alloy can be continuously tuned from ReSe2 (1.32 eV) to ReS2 (1.62 eV) by precisely controlling the growth conditions. Atomic-resolution scanning transmission electron microscopy reveals an interesting local atomic distribution in ReS2x Se2(1-x) alloy, where S and Se atoms are selectively occupied at different X sites in each Re-X6 octahedral unit cell with perfect matching between their atomic radius and space size of each X site. This structure is much attractive as it can induce the generation of highly desired localized electronic states in the 2D surface. The carrier type, threshold voltage, and carrier mobility of the alloy-based field effect transistors can be systematically modulated by tuning the alloy composition. Especially, for the first time the fully tunable conductivity of ReS2x Se2(1-x) alloys from n-type to bipolar and p-type is realized. Owing to the 1T' structure of ReS2x Se2(1-x) alloys, they exhibit strong anisotropic optical, electrical, and photoelectric properties. The controllable growth of monolayer ReS2x Se2(1-x) alloy with tunable bandgaps and electrical properties as well as superior anisotropic feature provides the feasibility for designing multifunctional 2D optoelectronic devices.
Collapse
Affiliation(s)
- Fangfang Cui
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Qingliang Feng
- Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education, Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P. R. China
| | - Jinhua Hong
- Nanostructures Research Laboratory, Japan Fine Ceramics Center, Atsuta, Nagoya, 456-8587, Japan
| | - Renyan Wang
- State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Yu Bai
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Xiaobo Li
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Dongyan Liu
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Yu Zhou
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
| | - Xing Liang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Xuexia He
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Zhongyue Zhang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Shengzhong Liu
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Zhibin Lei
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Zonghuai Liu
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Hua Xu
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China
| |
Collapse
|
39
|
Lin CL, Arafune R, Liu RY, Yoshimura M, Feng B, Kawahara K, Ni Z, Minamitani E, Watanabe S, Shi Y, Kawai M, Chiang TC, Matsuda I, Takagi N. Visualizing Type-II Weyl Points in Tungsten Ditelluride by Quasiparticle Interference. ACS NANO 2017; 11:11459-11465. [PMID: 29061038 DOI: 10.1021/acsnano.7b06179] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Weyl semimetals (WSMs) are classified into two types, type I and II, according to the topology of the Weyl point, where the electron and hole pockets touch each other. Tungsten ditelluride (WTe2) has garnered a great deal of attention as a strong candidate to be a type-II WSM. However, the Weyl points for WTe2 are located above the Fermi level, which has prevented us from identifying the locations and the connection to the Fermi arc surface states by using angle-resolved photoemission spectroscopy. Here, we present experimental proof that WTe2 is a type-II WSM. We measured energy-dependent quasiparticle interference patterns with a cryogenic scanning tunneling microscope, revealing the position of the Weyl point and its connection with the Fermi arc surface states, in agreement with prior theoretical predictions. Our results provide an answer to this crucial question and stimulate further exploration of the characteristics of WSMs.
Collapse
Affiliation(s)
- Chun-Liang Lin
- Department of Advanced Materials Science, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Ryuichi Arafune
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Ro-Ya Liu
- Institute for Solid State Physics, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Masato Yoshimura
- Department of Advanced Materials Science, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Baojie Feng
- Institute for Solid State Physics, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Kazuaki Kawahara
- Department of Advanced Materials Science, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Zeyuan Ni
- Department of Materials Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Emi Minamitani
- Department of Materials Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Satoshi Watanabe
- Department of Materials Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Youguo Shi
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Maki Kawai
- Department of Advanced Materials Science, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Tai-Chang Chiang
- Department of Physics, University of Illinois , Urbana, Illinois 61801, United States
| | - Iwao Matsuda
- Institute for Solid State Physics, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Noriaki Takagi
- Department of Advanced Materials Science, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| |
Collapse
|
40
|
Kamitani M, Bahramy MS, Nakajima T, Terakura C, Hashizume D, Arima T, Tokura Y. Superconductivity at the Polar-Nonpolar Phase Boundary of SnP with an Unusual Valence State. PHYSICAL REVIEW LETTERS 2017; 119:207001. [PMID: 29219367 DOI: 10.1103/physrevlett.119.207001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Indexed: 06/07/2023]
Abstract
Structural, magnetic, and electrical characterizations reveal that SnP with an unusual valence state (nominally Sn^{3+}) undergoes a ferroelectriclike structural transition from a simple NaCl-type structure to a polar tetragonal structure at approximately 250 K at ambient pressure. First-principles calculations indicate that the experimentally observed tetragonal distortion enhances the charge transfer from Sn to P, thereby making the polar tetragonal phase energetically more stable than the nonpolar cubic phase. Hydrostatic pressure is found to promptly suppress the structural phase transition in SnP, leading to the emergence of bulk superconductivity in a phase-competitive manner. These findings suggest that control of ferroelectriclike instability in a metal can be a promising way for creating novel superconductors.
Collapse
Affiliation(s)
- M Kamitani
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - M S Bahramy
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Hongo, Tokyo 113-8656, Japan
| | - T Nakajima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - C Terakura
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - D Hashizume
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - T Arima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - Y Tokura
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Hongo, Tokyo 113-8656, Japan
| |
Collapse
|
41
|
Tuning the electrical transport of type II Weyl semimetal WTe 2 nanodevices by Ga+ ion implantation. Sci Rep 2017; 7:12688. [PMID: 28978938 PMCID: PMC5627286 DOI: 10.1038/s41598-017-12865-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/14/2017] [Indexed: 11/08/2022] Open
Abstract
Here we introduce lattice defects in WTe2 by Ga+ implantation (GI), and study the effects of defects on the transport properties and electronic structures of the samples. Theoretical calculation shows that Te Frenkel defects is the dominant defect type, and Raman characterization results agree with this. Electrical transport measurements show that, after GI, significant changes are observed in magnetoresistance and Hall resistance. The classical two-band model analysis shows that both electron and hole concentration are significantly reduced. According to the calculated results, ion implantation leads to significant changes in the band structure and the Fermi surface of the WTe2. Our results indicate that defect engineering is an effective route of controlling the electronic properties of WTe2 devices.
Collapse
|
42
|
Yu P, Fu W, Zeng Q, Lin J, Yan C, Lai Z, Tang B, Suenaga K, Zhang H, Liu Z. Controllable Synthesis of Atomically Thin Type-II Weyl Semimetal WTe 2 Nanosheets: An Advanced Electrode Material for All-Solid-State Flexible Supercapacitors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29. [PMID: 28692747 DOI: 10.1002/adma.201701909] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 05/11/2017] [Indexed: 06/07/2023]
Abstract
Compared with 2D S-based and Se-based transition metal dichalcogenides (TMDs), Te-based TMDs display much better electrical conductivities, which will be beneficial to enhance the capacitances in supercapacitors. However, to date, the reports about the applications of Te-based TMDs in supercapacitors are quite rare. Herein, the first supercapacitor example of the Te-based TMD is reported: the type-II Weyl semimetal 1Td WTe2 . It is demonstrated that single crystals of 1Td WTe2 can be exfoliated into the nanosheets with 2-7 layers by liquid-phase exfoliation, which are assembled into air-stable films and further all-solid-state flexible supercapacitors. The resulting supercapacitors deliver a mass capacitance of 221 F g-1 and a stack capacitance of 74 F cm-3 . Furthermore, they also show excellent volumetric energy and power densities of 0.01 Wh cm-3 and 83.6 W cm-3 , respectively, superior to the commercial 4V/500 µAh Li thin-film battery and the commercial 3V/300 µAh Al electrolytic capacitor, in association with outstanding mechanical flexibility and superior cycling stability (capacitance retention of ≈91% after 5500 cycles). These results indicate that the 1Td WTe2 nanosheet is a promising flexible electrode material for high-performance energy storage devices.
Collapse
Affiliation(s)
- Peng Yu
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Wei Fu
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Qingsheng Zeng
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Junhao Lin
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8565, Japan
| | - Cheng Yan
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Zhuangchai Lai
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Bijun Tang
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Kazu Suenaga
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8565, Japan
| | - Hua Zhang
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Zheng Liu
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| |
Collapse
|
43
|
Sun Y, Fujisawa K, Lin Z, Lei Y, Mondschein JS, Terrones M, Schaak RE. Low-Temperature Solution Synthesis of Transition Metal Dichalcogenide Alloys with Tunable Optical Properties. J Am Chem Soc 2017; 139:11096-11105. [DOI: 10.1021/jacs.7b04443] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yifan Sun
- Department
of Chemistry, ‡Department of Physics, §Department of Materials Science and
Engineering, ∥Materials Research Institute, and ⊥Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kazunori Fujisawa
- Department
of Chemistry, ‡Department of Physics, §Department of Materials Science and
Engineering, ∥Materials Research Institute, and ⊥Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Zhong Lin
- Department
of Chemistry, ‡Department of Physics, §Department of Materials Science and
Engineering, ∥Materials Research Institute, and ⊥Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yu Lei
- Department
of Chemistry, ‡Department of Physics, §Department of Materials Science and
Engineering, ∥Materials Research Institute, and ⊥Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Jared S. Mondschein
- Department
of Chemistry, ‡Department of Physics, §Department of Materials Science and
Engineering, ∥Materials Research Institute, and ⊥Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mauricio Terrones
- Department
of Chemistry, ‡Department of Physics, §Department of Materials Science and
Engineering, ∥Materials Research Institute, and ⊥Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Raymond E. Schaak
- Department
of Chemistry, ‡Department of Physics, §Department of Materials Science and
Engineering, ∥Materials Research Institute, and ⊥Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|
44
|
Chang TR, Xu SY, Sanchez DS, Tsai WF, Huang SM, Chang G, Hsu CH, Bian G, Belopolski I, Yu ZM, Yang SA, Neupert T, Jeng HT, Lin H, Hasan MZ. Type-II Symmetry-Protected Topological Dirac Semimetals. PHYSICAL REVIEW LETTERS 2017; 119:026404. [PMID: 28753359 DOI: 10.1103/physrevlett.119.026404] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Indexed: 06/07/2023]
Abstract
The recent proposal of the type-II Weyl semimetal state has attracted significant interest. In this Letter, we propose the concept of the three-dimensional type-II Dirac fermion and theoretically identify this new symmetry-protected topological state in the large family of transition-metal icosagenides, MA_{3} (M=V, Nb, Ta; A=Al, Ga, In). We show that the VAl_{3} family features a pair of strongly Lorentz-violating type-II Dirac nodes and that each Dirac node can be split into four type-II Weyl nodes with chiral charge ±1 via symmetry breaking. Furthermore, we predict that the Landau level spectrum arising from the type-II Dirac fermions in VAl_{3} is distinct from that of known Dirac or Weyl semimetals. We also demonstrate a topological phase transition from a type-II Dirac semimetal to a quadratic Weyl semimetal or a topological crystalline insulator via crystalline distortions.
Collapse
Affiliation(s)
- Tay-Rong Chang
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Su-Yang Xu
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Daniel S Sanchez
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Wei-Feng Tsai
- Centre for Advanced 2D Materials and Graphene Research Centre National University of Singapore, 6 Science Drive 2, 117546 Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore, Singapore
| | - Shin-Ming Huang
- Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Guoqing Chang
- Centre for Advanced 2D Materials and Graphene Research Centre National University of Singapore, 6 Science Drive 2, 117546 Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore, Singapore
| | - Chuang-Han Hsu
- Centre for Advanced 2D Materials and Graphene Research Centre National University of Singapore, 6 Science Drive 2, 117546 Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore, Singapore
| | - Guang Bian
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Ilya Belopolski
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Zhi-Ming Yu
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Shengyuan A Yang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Titus Neupert
- Department of Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Horng-Tay Jeng
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Hsin Lin
- Centre for Advanced 2D Materials and Graphene Research Centre National University of Singapore, 6 Science Drive 2, 117546 Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore, Singapore
| | - M Zahid Hasan
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| |
Collapse
|
45
|
Lv YY, Cao L, Li X, Zhang BB, Wang K, Bin Pang BP, Ma L, Lin D, Yao SH, Zhou J, Chen YB, Dong ST, Liu W, Lu MH, Chen Y, Chen YF. Composition and temperature-dependent phase transition in miscible Mo 1-xW xTe 2 single crystals. Sci Rep 2017; 7:44587. [PMID: 28294191 PMCID: PMC5353676 DOI: 10.1038/srep44587] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 02/10/2017] [Indexed: 11/10/2022] Open
Abstract
Transition metal dichalcogenides (TMDs) WTe2 and MoTe2 with orthorhombic Td phase, being potential candidates as type-II Weyl semimetals, are attracted much attention recently. Here we synthesized a series of miscible Mo1-xWxTe2 single crystals by bromine vapor transport method. Composition-dependent X-ray diffraction and Raman spectroscopy, as well as composition and temperature-dependent resistivity prove that the tunable crystal structure (from hexagonal (2H), monoclinic (β) to orthorhombic (Td) phase) can be realized by increasing W content in Mo1-xWxTe2. Simultaneously the electrical property gradually evolves from semiconductor to semimetal behavior. Temperature-dependent Raman spectroscopy proves that temperature also can induce the structural phase transition from β to Td phase in Mo1-xWxTe2 crystals. Based on aforementioned characterizations, we map out the temperature and composition dependent phase diagram of Mo1-xWxTe2 system. In addition, a series of electrical parameters, such as carrier type, carrier concentration and mobility, have also been presented. This work offers a scheme to accurately control structural phase in Mo1-xWxTe2 system, which can be used to explore type-II Weyl semimetal, as well as temperature/composition controlled topological phase transition therein.
Collapse
Affiliation(s)
- Yang-Yang Lv
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
| | - Lin Cao
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
| | - Xiao Li
- National Laboratory of Solid State Microstructures & Department of Physics, Nanjing University, Nanjing 210093 China
| | - Bin-Bin Zhang
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
| | - Kang Wang
- National Laboratory of Solid State Microstructures & Department of Physics, Nanjing University, Nanjing 210093 China
| | - B P Bin Pang
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
| | - Ligang Ma
- National Laboratory of Solid State Microstructures & Department of Physics, Nanjing University, Nanjing 210093 China
| | - Dajun Lin
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
| | - Shu-Hua Yao
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
| | - Jian Zhou
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
| | - Y. B. Chen
- National Laboratory of Solid State Microstructures & Department of Physics, Nanjing University, Nanjing 210093 China
| | - Song-Tao Dong
- Institute of materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 China
| | - Wenchao Liu
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
- Institute of Advanced Materials (IAM) & Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211800 China
| | - Ming-Hui Lu
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
| | - Yulin Chen
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 200031, China
- State Key Laboratory of Low Dimensional Quantum Physics, Collaborative Innovation Center of Quantum Matter and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yan-Feng Chen
- National Laboratory of Solid State Microstructures & Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 China
- Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing, 210093 China
| |
Collapse
|
46
|
Niemann AC, Gooth J, Wu SC, Bäßler S, Sergelius P, Hühne R, Rellinghaus B, Shekhar C, Süß V, Schmidt M, Felser C, Yan B, Nielsch K. Chiral magnetoresistance in the Weyl semimetal NbP. Sci Rep 2017; 7:43394. [PMID: 28262790 PMCID: PMC5338026 DOI: 10.1038/srep43394] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/20/2017] [Indexed: 11/13/2022] Open
Abstract
NbP is a recently realized Weyl semimetal (WSM), hosting Weyl points through which conduction and valence bands cross linearly in the bulk and exotic Fermi arcs appear. The most intriguing transport phenomenon of a WSM is the chiral anomaly-induced negative magnetoresistance (NMR) in parallel electric and magnetic fields. In intrinsic NbP the Weyl points lie far from the Fermi energy, making chiral magneto-transport elusive. Here, we use Ga-doping to relocate the Fermi energy in NbP sufficiently close to the W2 Weyl points, for which the different Fermi surfaces are verified by resultant quantum oscillations. Consequently, we observe a NMR for parallel electric and magnetic fields, which is considered as a signature of the chiral anomaly in condensed-matter physics. The NMR survives up to room temperature, making NbP a versatile material platform for the development of Weyltronic applications.
Collapse
Affiliation(s)
- Anna Corinna Niemann
- Institute of Nanostructure and Solid State Physics, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg, Germany.,Leibniz Institute for Solid State and Materials Research Dresden, Institute for Metallic Materials, Helmholtzstraße 20, 01069 Dresden, Germany
| | - Johannes Gooth
- Institute of Nanostructure and Solid State Physics, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg, Germany.,IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Shu-Chun Wu
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Svenja Bäßler
- Institute of Nanostructure and Solid State Physics, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg, Germany
| | - Philip Sergelius
- Institute of Nanostructure and Solid State Physics, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg, Germany
| | - Ruben Hühne
- Leibniz Institute for Solid State and Materials Research Dresden, Institute for Metallic Materials, Helmholtzstraße 20, 01069 Dresden, Germany
| | - Bernd Rellinghaus
- Leibniz Institute for Solid State and Materials Research Dresden, Institute for Metallic Materials, Helmholtzstraße 20, 01069 Dresden, Germany
| | - Chandra Shekhar
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Vicky Süß
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Marcus Schmidt
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Binghai Yan
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany.,Max Planck Institute for Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - Kornelius Nielsch
- Institute of Nanostructure and Solid State Physics, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg, Germany.,Leibniz Institute for Solid State and Materials Research Dresden, Institute for Metallic Materials, Helmholtzstraße 20, 01069 Dresden, Germany
| |
Collapse
|