1
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Thomsen JD, Han MG, Penn AN, Foucher AC, Geiwitz M, Burch KS, Dekanovsky L, Sofer Z, Liu Y, Petrovic C, Ross FM, Zhu Y, Narang P. Effect of Surface Oxidation and Crystal Thickness on the Magnetic Properties and Magnetic Domain Structures of Cr 2Ge 2Te 6. ACS NANO 2024; 18:13458-13467. [PMID: 38739873 DOI: 10.1021/acsnano.3c09858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
van der Waals (vdW) magnetic materials, such as Cr2Ge2Te6 (CGT), show promise for memory and logic applications. This is due to their broadly tunable magnetic properties and the presence of topological magnetic features such as skyrmionic bubbles. A systematic study of thickness and oxidation effects on magnetic domain structures is important for designing devices and vdW heterostructures for practical applications. Here, we investigate thickness effects on magnetic properties, magnetic domains, and bubbles in oxidation-controlled CGT crystals. We find that CGT exposed to ambient conditions for 5 days forms an oxide layer approximately 5 nm thick. This oxidation leads to a significant increase in the oxidation state of the Cr ions, indicating a change in local magnetic properties. This is supported by real-space magnetic texture imaging through Lorentz transmission electron microscopy. By comparing the thickness-dependent saturation field of oxidized and pristine crystals, we find that oxidation leads to a nonmagnetic surface layer that is thicker than the oxide layer alone. We also find that the stripe domain width and skyrmionic bubble size are strongly affected by the crystal thickness in pristine crystals. These findings underscore the impact of thickness and surface oxidation on the properties of CGT, such as saturation field and domain/skyrmionic bubble size, and suggest a pathway for manipulating magnetic properties through a controlled oxidation process.
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Affiliation(s)
- Joachim Dahl Thomsen
- Division of Physical Sciences, College of Letters and Science, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Myung-Geun Han
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Aubrey N Penn
- MIT.nano, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexandre C Foucher
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Michael Geiwitz
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Kenneth Stephen Burch
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Lukas Dekanovsky
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, Prague 6 166 28, Czech Republic
| | - Zdeněk Sofer
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, Prague 6 166 28, Czech Republic
| | - Yu Liu
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, United States
- Center for Correlated Matter and School of Physics, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Cedomir Petrovic
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, United States
- Shanghai Key Laboratory of Material Frontiers Research in Extreme Environments (MFree), Shanghai Advanced Research in Physical Sciences (SHARPS), Pudong, Shanghai 201203, People's Republic of China
| | - Frances M Ross
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Prineha Narang
- Division of Physical Sciences, College of Letters and Science, University of California, Los Angeles, Los Angeles, California 90095, United States
- Electrical and Computer Engineering Department, University of California, Los Angeles, Los Angeles, California 90095, United States
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2
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Ma S, Li G, Li Z, Wang T, Zhang Y, Li N, Chen H, Zhang N, Liu W, Huang Y. Negative Photoconductivity of Fe 3GeTe 2 Crystal with Native Heterostructure for Ultraviolet to Terahertz Ultra-Broadband Photodetection. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2305709. [PMID: 38207342 DOI: 10.1002/adma.202305709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 12/10/2023] [Indexed: 01/13/2024]
Abstract
Gaining insight into the photoelectric behavior of ferromagnetic materials is significant for comprehensively grasping their intrinsic properties and broadening future application fields. Here, through a specially designed Fe3GeTe2/O-Fe3GeTe2 heterostructure, first, the broad-spectrum negative photoconductivity phenomenon of ferromagnetic nodal line semimetal Fe3GeTe2 is reported that covers UV-vis-infrared-terahertz bands (355 nm to 3000 µm), promising to compensate for the inadequacies of traditional optoelectronic devices. The significant suppression of photoexcitation conductivity is revealed to arise from the semimetal/oxidation (sMO) interface-assisted dual-response mechanism, in which the electron excitation origins from the semiconductor photoconductivity effect in high-energy photon region, and semimetal topological band-transition in low-energy photon region. High responsivities ranging from 103 to 100 mA W-1 are acquired within ultraviolet-terahertz bands under ±0.1 V bias voltage at room temperature. Notably, the responsivity of 2.572 A W-1 at 3000 µm (0.1 THz) and the low noise equivalent power of 26 pW Hz-1/2 surpass most state-of-the-art mainstream terahertz detectors. This research provides a new perspective for revealing the photoelectric conversion properties of Fe3GeTe2 crystal and paves the way for the development of spin-optoelectronic devices.
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Affiliation(s)
- Suping Ma
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin, 300350, P. R. China
| | - Guanghao Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin, 300350, P. R. China
| | - Zhuo Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin, 300350, P. R. China
| | - Tingyuan Wang
- Institute of Modern Optics, Key Laboratory of Optical Information Science and Technology, Ministry of Education, Nankai University, Tianjin, 300350, P. R. China
| | - Yawen Zhang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin, 300350, P. R. China
| | - Ningning Li
- Institute of Modern Optics, Key Laboratory of Optical Information Science and Technology, Ministry of Education, Nankai University, Tianjin, 300350, P. R. China
| | - Haisheng Chen
- Institute of Modern Optics, Key Laboratory of Optical Information Science and Technology, Ministry of Education, Nankai University, Tianjin, 300350, P. R. China
| | - Nan Zhang
- Institute of Modern Optics, Key Laboratory of Optical Information Science and Technology, Ministry of Education, Nankai University, Tianjin, 300350, P. R. China
| | - Weiwei Liu
- Institute of Modern Optics, Key Laboratory of Optical Information Science and Technology, Ministry of Education, Nankai University, Tianjin, 300350, P. R. China
| | - Yi Huang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin, 300350, P. R. China
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3
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Zeng X, Ye G, Yang F, Ye Q, Zhang L, Ma B, Liu Y, Xie M, Liu Y, Wang X, Hao Y, Han G. Tunable asymmetric magnetoresistance in an Fe 3GeTe 2/graphite/Fe 3GeTe 2 lateral spin valve. NANOSCALE 2023. [PMID: 38018435 DOI: 10.1039/d3nr04069k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
van der Waals (vdW) ferromagnetic heterojunctions, characterized by an ultraclean device interface and the absence of lattice matching, have emerged as indispensable and efficient building blocks for future spintronic devices. In this study, we present a seldom observed antisymmetric magnetoresistance (MR) behavior with three distinctive resistance states in a lateral van der Waals (vdW) structure comprising Fe3GeTe2 (FGT)/graphite/FGT. In contrast to traditional spin valves governed by the magnetization configurations of ferromagnetic electrodes (FEs), this distinct feature can be attributed to the interaction between FGT and the FGT/graphite interface, which is primarily influenced by the internal spin-momentum locking effect. Furthermore, modulation of the MR behavior is accomplished by employing the coupling between antiferromagnetic and ferromagnetic materials to adjust the coercive fields of two FEs subsequent to the in situ growth of an FGT oxide layer on FGT. This study elucidates the device physics and mechanism of property modulation in lateral spin valves and holds the potential for advancing the development of gate-tunable spintronic devices and next-generation integrated circuits.
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Affiliation(s)
- Xiangyu Zeng
- Hangzhou Institute of Technology, Xidian University, Hangzhou, 311200, China.
- State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China
| | - Ge Ye
- Center for correlated matter and Department of Physics, Zhejiang University, Hangzhou, 310027, China
| | - Fazhi Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Qikai Ye
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Liang Zhang
- Research Center for Humanoid Sensing and Perception, Zhejiang Lab, Hangzhou, 311100, China
| | - Boyang Ma
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Yulu Liu
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Mengwei Xie
- Center for correlated matter and Department of Physics, Zhejiang University, Hangzhou, 310027, China
| | - Yan Liu
- Hangzhou Institute of Technology, Xidian University, Hangzhou, 311200, China.
- State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China
| | - Xiaozhi Wang
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Yue Hao
- Hangzhou Institute of Technology, Xidian University, Hangzhou, 311200, China.
- State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China
| | - Genquan Han
- Hangzhou Institute of Technology, Xidian University, Hangzhou, 311200, China.
- State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China
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4
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Ren H, Lan M. Progress and Prospects in Metallic Fe xGeTe 2 (3 ≤ x ≤ 7) Ferromagnets. Molecules 2023; 28:7244. [PMID: 37959664 PMCID: PMC10649090 DOI: 10.3390/molecules28217244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/05/2023] [Accepted: 10/21/2023] [Indexed: 11/15/2023] Open
Abstract
Thermal fluctuations in two-dimensional (2D) isotropy systems at non-zero finite temperatures can destroy the long-range (LR) magnetic order due to the mechanisms addressed in the Mermin-Wanger theory. However, the magnetic anisotropy related to spin-orbit coupling (SOC) may stabilize magnetic order in 2D systems. Very recently, 2D FexGeTe2 (3 ≤ x ≤ 7) with a high Curie temperature (TC) has not only undergone significant developments in terms of synthetic methods and the control of ferromagnetism (FM), but is also being actively explored for applications in various devices. In this review, we introduce six experimental methods, ten ferromagnetic modulation strategies, and four spintronic devices for 2D FexGeTe2 materials. In summary, we outline the challenges and potential research directions in this field.
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Affiliation(s)
- Hongtao Ren
- School of Materials Science and Engineering, Liaocheng University, Liaocheng 252000, China
| | - Mu Lan
- College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China
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5
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Chyczewski ST, Shi J, Lee H, Furlanetto PF, Xu K, van der Zande AM, Zhu W. Probing antiferromagnetism in exfoliated Fe 3GeTe 2 using magneto-transport measurements. NANOSCALE 2023; 15:14061-14067. [PMID: 37581284 DOI: 10.1039/d3nr01022h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
Among the material class of van der Waals magnets, Fe3GeTe2 (FGT) has emerged as one of the most studied owing to features such as its relatively high Curie temperature, metallic nature, and large spin polarization. Though most studies only investigate its explicitly ferromagnetic properties, FGT is also predicted to have an antiferromagnetic phase in the out-of-plane direction emerging at temperatures below 150 K, leading to a blend of ferromagnetic and antiferromagnetic ordering. Here, we explore the emergence of this phase and its effects in FGT/h-BN heterostructures using magneto-transport measurements. The devices' anomalous Hall and magnetoresistance responses exhibit a complex trend with temperature that is consistent with multiple magnetic phases. In addition to the usual out-of-plane sensing, we also rotate the applied field to the in-plane direction and observe behavior resembling the planar topological Hall effect. Intriguingly, this response follows a similar temperature trend to the out-of-plane response. We also use the out-of-plane anomalous Hall response to show that, at sufficiently low temperatures, both positive and negative field-cooling results in an increased saturation Hall resistance. Such a field-cooling divergence is consistent with antiferromagnetic ordering resulting in a spin-glass like state in the sample. In addition to providing insight into one of the most exciting candidate materials for 2D magnetic devices, our work demonstrates the power of magneto-transport measurements to probe complex behavior in vdW magnets where common magnetometry techniques used on bulk samples may not be viable.
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Affiliation(s)
- Stasiu T Chyczewski
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| | - Ji Shi
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| | - Hanwool Lee
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| | - Paolo F Furlanetto
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Kai Xu
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| | - Arend M van der Zande
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Wenjuan Zhu
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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6
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Lv H, da Silva A, Figueroa AI, Guillemard C, Aguirre IF, Camosi L, Aballe L, Valvidares M, Valenzuela SO, Schubert J, Schmidbauer M, Herfort J, Hanke M, Trampert A, Engel-Herbert R, Ramsteiner M, Lopes JMJ. Large-Area Synthesis of Ferromagnetic Fe 5- x GeTe 2 /Graphene van der Waals Heterostructures with Curie Temperature above Room Temperature. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302387. [PMID: 37231567 DOI: 10.1002/smll.202302387] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/10/2023] [Indexed: 05/27/2023]
Abstract
Van der Waals (vdW) heterostructures combining layered ferromagnets and other 2D crystals are promising building blocks for the realization of ultracompact devices with integrated magnetic, electronic, and optical functionalities. Their implementation in various technologies depends strongly on the development of a bottom-up scalable synthesis approach allowing for realizing highly uniform heterostructures with well-defined interfaces between different 2D-layered materials. It is also required that each material component of the heterostructure remains functional, which ideally includes ferromagnetic order above room temperature for 2D ferromagnets. Here, it is demonstrated that the large-area growth of Fe5- x GeTe2 /graphene heterostructures is achieved by vdW epitaxy of Fe5- x GeTe2 on epitaxial graphene. Structural characterization confirms the realization of a continuous vdW heterostructure film with a sharp interface between Fe5- x GeTe2 and graphene. Magnetic and transport studies reveal that the ferromagnetic order persists well above 300 K with a perpendicular magnetic anisotropy. In addition, epitaxial graphene on SiC(0001) continues to exhibit a high electronic quality. These results represent an important advance beyond nonscalable flake exfoliation and stacking methods, thus marking a crucial step toward the implementation of ferromagnetic 2D materials in practical applications.
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Affiliation(s)
- Hua Lv
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, 10117, Berlin, Germany
| | - Alessandra da Silva
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, 10117, Berlin, Germany
| | - Adriana I Figueroa
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
| | - Charles Guillemard
- ALBA Synchrotron Light Source, Cerdanyola del Valles, Barcelona, 08290, Spain
| | - Iván Fernández Aguirre
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
- Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Lorenzo Camosi
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
| | - Lucia Aballe
- ALBA Synchrotron Light Source, Cerdanyola del Valles, Barcelona, 08290, Spain
| | - Manuel Valvidares
- ALBA Synchrotron Light Source, Cerdanyola del Valles, Barcelona, 08290, Spain
| | - Sergio O Valenzuela
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, 08010, Spain
| | - Jürgen Schubert
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, 52425, Jülich, Germany
| | | | - Jens Herfort
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, 10117, Berlin, Germany
| | - Michael Hanke
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, 10117, Berlin, Germany
| | - Achim Trampert
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, 10117, Berlin, Germany
| | - Roman Engel-Herbert
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, 10117, Berlin, Germany
| | - Manfred Ramsteiner
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, 10117, Berlin, Germany
| | - Joao Marcelo J Lopes
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, 10117, Berlin, Germany
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7
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Choi EM, Kim T, Cho BW, Lee YH. Proximity-Induced Tunable Magnetic Order at the Interface of All-van der Waals-Layered Heterostructures. ACS NANO 2023; 17:15656-15665. [PMID: 37523780 DOI: 10.1021/acsnano.3c02764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Spin-orbit coupling (SOC) plays a crucial role in controlling the spin-charge conversion efficiency, spin torque, and complex magnetic spin structures. In this study, we investigate the interplay between SOC and ferromagnetism in heterostructures of large-SOC and magnetic materials. We highlight the importance of the SOC-proximity effect on magnetic ordering in all-van der Waals-layered heterostructures, specifically Fe3GeTe2(FGT)/monolayer W1-xVxSe2 (x = 0 and 0.05). By increasing the SOC strength, we demonstrate various magnetic orderings induced at the interface of the heterostructure, including spin-flop, spin-flip, and inverted magnetization. Moreover, we show a sharp magnetic switching from antiferromagnetic state to ferromagnetic state in FGT/W0.95V0.05Se2, which is characteristic of the synthetic antiferromagnetic structure. This proof-of-concept result offers the possibility of interface-tailoring spintronics, including two-dimensional magnetoresistive random access memory toggle switching. Our findings provide insight into the design and development of next-generation spintronic devices by exploiting the interplay between SOC and magnetic ordering in all-van der Waals-layered heterostructures.
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Affiliation(s)
- Eun-Mi Choi
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Taesoo Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Byeong Wook Cho
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Sungkyunkwan University, Suwon 16419, Republic of Korea
- Advanced Facility Center for Quantum Technology, Sungkyunkwan University, Suwon 16419, Republic of Korea
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8
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Ren H, Xiang G. Strain Engineering of Intrinsic Ferromagnetism in 2D van der Waals Materials. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2378. [PMID: 37630963 PMCID: PMC10459406 DOI: 10.3390/nano13162378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/09/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023]
Abstract
Since the discovery of the low-temperature, long-range ferromagnetic order in monolayers Cr2Ge2Te6 and CrI3, many efforts have been made to achieve a room temperature (RT) ferromagnet. The outstanding deformation ability of two-dimensional (2D) materials provides an exciting way to mediate their intrinsic ferromagnetism (FM) with strain engineering. Here, we summarize the recent progress of strain engineering of intrinsic FM in 2D van der Waals materials. First, we introduce how to explain the strain-mediated intrinsic FM on Cr-based and Fe-based 2D van der Waals materials through ab initio Density functional theory (DFT), and how to calculate magnetic anisotropy energy (MAE) and Curie temperature (TC) from the interlayer exchange coupling J. Subsequently, we focus on numerous attempts to apply strain to 2D materials in experiments, including wrinkle-induced strain, flexible substrate bending or stretching, lattice mismatch, electrostatic force and field-cooling. Last, we emphasize that this field is still in early stages, and there are many challenges that need to be overcome. More importantly, strengthening the guideline of strain-mediated FM in 2D van der Waals materials will promote the development of spintronics and straintronics.
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Affiliation(s)
- Hongtao Ren
- School of Materials Science and Engineering, Liaocheng University, Hunan Road No. 1, Liaocheng 252000, China
| | - Gang Xiang
- College of Physics, Sichuan University, Wangjiang Road No. 29, Chengdu 610064, China
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9
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Wang H, Lu H, Guo Z, Li A, Wu P, Li J, Xie W, Sun Z, Li P, Damas H, Friedel AM, Migot S, Ghanbaja J, Moreau L, Fagot-Revurat Y, Petit-Watelot S, Hauet T, Robertson J, Mangin S, Zhao W, Nie T. Interfacial engineering of ferromagnetism in wafer-scale van der Waals Fe 4GeTe 2 far above room temperature. Nat Commun 2023; 14:2483. [PMID: 37120587 PMCID: PMC10148834 DOI: 10.1038/s41467-023-37917-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 04/05/2023] [Indexed: 05/01/2023] Open
Abstract
Despite recent advances in exfoliated vdW ferromagnets, the widespread application of 2D magnetism requires a Curie temperature (Tc) above room temperature as well as a stable and controllable magnetic anisotropy. Here we demonstrate a large-scale iron-based vdW material Fe4GeTe2 with the Tc reaching ~530 K. We confirmed the high-temperature ferromagnetism by multiple characterizations. Theoretical calculations suggested that the interface-induced right shift of the localized states for unpaired Fe d electrons is the reason for the enhanced Tc, which was confirmed by ultraviolet photoelectron spectroscopy. Moreover, by precisely tailoring Fe concentration we achieved arbitrary control of magnetic anisotropy between out-of-plane and in-plane without inducing any phase disorders. Our finding sheds light on the high potential of Fe4GeTe2 in spintronics, which may open opportunities for room-temperature application of all-vdW spintronic devices.
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Affiliation(s)
- Hangtian Wang
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Haichang Lu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
- Engineering Department, Cambridge University, Cambridge, CB2 1PZ, UK.
| | - Zongxia Guo
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Ang Li
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peichen Wu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Jing Li
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Weiran Xie
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhimei Sun
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peng Li
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
| | - Héloïse Damas
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Anna Maria Friedel
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Sylvie Migot
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Jaafar Ghanbaja
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Luc Moreau
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | | | | | - Thomas Hauet
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - John Robertson
- Engineering Department, Cambridge University, Cambridge, CB2 1PZ, UK
| | - Stéphane Mangin
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France.
| | - Weisheng Zhao
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
| | - Tianxiao Nie
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
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10
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Ma S, Li G, Li Z, Zhang Y, Lu H, Gao Z, Wu J, Long G, Huang Y. 2D Magnetic Semiconductor Fe 3GeTe 2 with Few and Single Layers with a Greatly Enhanced Intrinsic Exchange Bias by Liquid-Phase Exfoliation. ACS NANO 2022; 16:19439-19450. [PMID: 36288432 DOI: 10.1021/acsnano.2c09143] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A 2D van der Waals (vdW) magnet can get rid of the constraints of lattice matching and compatibility and then create a variety of vdW heterostructures, which provides a opportunity for spintronic devices. However, the ability to reliably exfoliate large, high-quality vdW ferromagnetic Fe3GeTe2 (FGT) nanoflakes in scaled-up production is severely limited. Herein, an efficient and stable three-stage sonication-assisted liquid-phase exfoliation was developed for mass preparation of high-structural-integrity few- and single-layer FGT nanoflakes with a greatly enhanced intrinsic exchange bias. The three stages include slicing crystals, weakening interlayer vdW forces, and using ultrasonic cavitation. The highest yield of FGT nanoflakes is 22.3 wt % with single layers accounting for 6%. The size is controllable, and several micrometers, tens of micrometers, and a maximum of 103 μm are available. The 200 mg level output has overcome the limitations of mechanical exfoliation and molecular beam epitaxy in economically amplificated production. An intrinsic exchange bias is observed in the restacked nanoflakes due to the magnetic proximity on the interface of the FGT/natural surface oxide layer. The material reaches 578 Oe (2 K) and 2300 Oe after further oxidation, at least 250% higher than other precisely tailored vdW magnetic heterostructures. In addition, the unusual semiconductivity of the liquid-phase exfoliated FGT nanoflakes is reported. This work skillfully utilizes oxidation to enhance the potential of FGT for large-scale spintronics, optoelectronics, efficient data storage, and various extended applications, and it is beneficial for exfoliating other promising magnetic vdW materials.
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Affiliation(s)
- Suping Ma
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Guanghao Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Zhuo Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Yawen Zhang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Haolin Lu
- School of Materials Science and Engineering, National Institute for Advanced Materials, Renewable Energy Conversion and Storage Center (RECAST), Nankai University, Tianjin300350, People's Republic of China
| | - Zhansheng Gao
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Jinxiong Wu
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, Beijing100871, People's Republic of China
| | - Guankui Long
- School of Materials Science and Engineering, National Institute for Advanced Materials, Renewable Energy Conversion and Storage Center (RECAST), Nankai University, Tianjin300350, People's Republic of China
| | - Yi Huang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
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11
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Cho K, Lee T, Chung S. Inkjet printing of two-dimensional van der Waals materials: a new route towards emerging electronic device applications. NANOSCALE HORIZONS 2022; 7:1161-1176. [PMID: 35894100 DOI: 10.1039/d2nh00162d] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Two-dimensional (2D) van der Waals (vdW) materials are considered one of the most promising candidates to realize emerging electrical applications. Although until recently, much effort has been dedicated to demonstrating high-performance single 2D vdW devices, associated with rapid progress in 2D vdW materials, demands for their large-scale practical applications have noticeably increased from a manufacturing perspective. Drop-on-demand inkjet printing can be the most feasible solution by exploiting the advantages of layered 2D contacts and advanced 2D vdW ink formulations. This review presents recent achievements in inkjet-printed 2D vdW material-based device applications. A brief introduction to 2D vdW materials and inkjet printing principles, followed by various ink formulation methods, is first presented. Then, the state-of-the-art inkjet-printed 2D vdW device applications and their remaining technical issues are highlighted. Finally, prospects and challenges to be overcome to demonstrate fully inkjet-printed, high-performance 2D vdW devices are also discussed.
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Affiliation(s)
- Kyungjune Cho
- Soft Hybrid Materials Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea.
| | - Takhee Lee
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Korea
| | - Seungjun Chung
- Soft Hybrid Materials Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea.
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul, 02447, Korea
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12
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Li G, Ma S, Li Z, Zhang Y, Diao J, Xia L, Zhang Z, Huang Y. High-Quality Ferromagnet Fe 3GeTe 2 for High-Efficiency Electromagnetic Wave Absorption and Shielding with Wideband Radar Cross Section Reduction. ACS NANO 2022; 16:7861-7879. [PMID: 35467351 DOI: 10.1021/acsnano.2c00512] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A high-quality Fe3GeTe2 single crystal with good electrical, magnetic, and electromagnetic wave absorption and shielding properties was prepared in a large quantity (10 g level) by solid-phase sintering and recrystallization method, which would promote its in-depth research and practical application. It has good room-temperature electrical properties with a mobility of 42 cm2/V·s, a sheet (bulk) carrier concentration of +1.64 × 1018 /cm2 (+3.28 × 1020 /cm3), and a conductivity of 2196.35 S/cm. Also, a Curie temperature of 238 K indicates the high magnetic transition temperature and a paramagnetic Curie temperature of 301 K shows the large ferromagnetic-paramagnetic transition zone induced by the residual short-range ferromagnetic domains. Particularly, Fe3GeTe2 is in a loosely packed state when used as a loss agent; the electromagnetic wave absorption with a reflection loss of -34.7 dB at 3.66 GHz under thin thickness was shown. Meanwhile, the absorption band can be effectively regulated by varying the thickness. Moreover, Fe3GeTe2 in a close-packed state exhibits terahertz shielding values of 75.1 and 103.2 dB at very thin thicknesses of 70 and 380 μm, and the average shielding value is higher than 47 dB, covering the entire bandwidth from 0.1 to 3.0 THz. Furthermore, by using Fe3GeTe2 as a patch, the wideband radar cross-section can be effectively reduced by up to 33 dBsm. Resultantly, Fe3GeTe2 will be a promising candidate in the electromagnetic protection field.
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Affiliation(s)
- Guanghao Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Suping Ma
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Zhuo Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Yawen Zhang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Jianglin Diao
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Lun Xia
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Zhiwei Zhang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Yi Huang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
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13
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Zhang T, Zhang Y, Huang M, Li B, Sun Y, Qu Z, Duan X, Jiang C, Yang S. Tuning the Exchange Bias Effect in 2D van der Waals Ferro-/Antiferromagnetic Fe 3 GeTe 2 /CrOCl Heterostructures. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105483. [PMID: 35238180 PMCID: PMC9009105 DOI: 10.1002/advs.202105483] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/14/2022] [Indexed: 06/01/2023]
Abstract
The exchange bias effect is extremely expected in 2D van der Waals (vdW) ferromagnetic (FM)/antiferromagnetic (AFM) heterostructures due to the high-quality interface. CrOCl possesses strong magnetic anisotropy at 2D limit, and is an ideal antiferromagnet for constructing FM/AFM heterostructures to explore the exchange bias effect. Here, the exchange bias effect in Fe3 GeTe2 (FGT)/CrOCl heterostructures through both anomalous Hall effect (AHE) and reflective magnetic circular dichroism (RMCD) measurements is studied. In the AHE measurements, the exchange bias field (HEB ) at 3 K exhibits a distinct increase from ≈150 Oe to ≈450 Oe after air exposure, and such variation is attributed to the formation of an oxidized layer in FGT by analyzing the cross-sectional microstructure. The HEB is successfully tuned by changing the FGT/CrOCl thickness and the cooling field. Furthermore, a larger HEB of ≈750 Oe at 1.7 K in FGT/CrOCl heterostructure through RMCD measurements is observed, and it is proposed that the larger HEB in RMCD measurements is related to the distribution of uncompensated spins at the interface. This work reveals several intriguing phenomena of the exchange bias effect in 2D vdW magnetic systems, which paves the way for the study of related spintronic devices.
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Affiliation(s)
- Tianle Zhang
- School of Materials Science and EngineeringBeihang UniversityBeijing100191P. R. China
| | - Yujun Zhang
- Department of PhysicsSouthern University of Science and TechnologyShenzhenGuangdong518055P. R. China
| | - Mingyuan Huang
- Department of PhysicsSouthern University of Science and TechnologyShenzhenGuangdong518055P. R. China
| | - Bo Li
- Hunan Key Laboratory of Two‐Dimensional MaterialsSchool of Physics and ElectronicsHunan UniversityChangshaHunan410082P. R. China
| | - Yinghui Sun
- Beijing Key Laboratory for Magneto‐Photoelectrical Composite and Interface ScienceSchool of Mathematics and PhysicsUniversity of Science and Technology BeijingBeijing100083P. R. China
| | - Zhe Qu
- Anhui Key Laboratory of Condensed Matter Physics at Extreme ConditionsHigh Magnetic Field LaboratoryChinese Academy of SciencesHefeiAnhui230031P. R. China
| | - Xidong Duan
- State Key Laboratory for Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan UniversityChangshaHunan419982P. R. China
| | - Chengbao Jiang
- School of Materials Science and EngineeringBeihang UniversityBeijing100191P. R. China
| | - Shengxue Yang
- School of Materials Science and EngineeringBeihang UniversityBeijing100191P. R. China
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14
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Hu L, Zhou J, Hou Z, Su W, Yang B, Li L, Yan M. Polymer-buried van der Waals magnets for promising wearable room-temperature spintronics. MATERIALS HORIZONS 2021; 8:3306-3314. [PMID: 34751291 DOI: 10.1039/d1mh01439k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The demand for high-performance spintronic devices has boosted intense research on the manipulation of magnetism in van der Waals (vdW) magnets. Despite great efforts, robust ferromagnetic transitions above room temperature still face significant hurdles. Strain engineering can reversibly regulate magnetic exchange, but the degree of regulation is still impractical for most magnetic applications. Hereby we employ a large-strain transferrer to produce tunable strains of up to 4.7%, which induces authentic room-temperature ferromagnetism in large-area Fe3GeTe2 nanoflakes with 20-fold improvement in magnetization. The record increment of the Curie temperature (TC) of well above 400 K originates from the strain-enhanced magnetic anisotropy and excellent magnetoelastic coupling. The correlation between the emerging ferromagnetism and Raman spectral evolution is also established, which complements well the TC phase diagram in a large-strain region. In addition, an unusual exchange bias effect with a vertical magnetization shift is tracked for the first time upon bending, which reveals the hidden competition between antiferromagnetic and ferromagnetic coupling. The reversible strain manipulation of single-domain ferromagnetic order in a single nanoflake further opens up a route to develop low-power wearable spintronic devices. The findings here provide vast opportunities to exploit the possibility of practical applications of more vdW magnets.
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Affiliation(s)
- Liang Hu
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China
| | - Jian Zhou
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
| | - Zhipeng Hou
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
| | - Weitao Su
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
| | - Bingzhang Yang
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
| | - Lingwei Li
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
| | - Mi Yan
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China
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15
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Rahman S, Torres JF, Khan AR, Lu Y. Recent Developments in van der Waals Antiferromagnetic 2D Materials: Synthesis, Characterization, and Device Implementation. ACS NANO 2021; 15:17175-17213. [PMID: 34779616 DOI: 10.1021/acsnano.1c06864] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Magnetism in two dimensions is one of the most intriguing and alluring phenomena in condensed matter physics. Atomically thin 2D materials have emerged as a promising platform for exploring magnetic properties, leading to the development of essential technologies such as supercomputing and data storage. Arising from spin and charge dynamics in elementary particles, magnetism has also unraveled promising advances in spintronic devices and spin-dependent optoelectronics and photonics. Recently, antiferromagnetism in 2D materials has received extensive attention, leading to significant advances in their understanding and emerging applications; such materials have zero net magnetic moment yet are internally magnetic. Several theoretical and experimental approaches have been proposed to probe, characterize, and modulate the magnetic states efficiently in such systems. This Review presents the latest developments and current status for tuning the magnetic properties in distinct 2D van der Waals antiferromagnets. Various state-of-the-art optical techniques deployed to investigate magnetic textures and dynamics are discussed. Furthermore, device concepts based on antiferromagnetic spintronics are scrutinized. We conclude with remarks on related challenges and technological outlook in this rapidly expanding field.
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Affiliation(s)
- Sharidya Rahman
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Juan F Torres
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Ahmed Raza Khan
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Yuerui Lu
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
- ARC Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Acton, ACT 2601, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), ANU node, Canberra, ACT 2601, Australia
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16
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Unconventional Hall effect and its variation with Co-doping in van der Waals Fe 3GeTe 2. Sci Rep 2021; 11:14121. [PMID: 34238967 PMCID: PMC8266818 DOI: 10.1038/s41598-021-93402-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/16/2021] [Indexed: 11/18/2022] Open
Abstract
Two-dimensional (2D) van der Waals (vdW) magnetic materials have attracted a lot of attention owing to the stabilization of long range magnetic order down to atomic dimensions, and the prospect of novel spintronic devices with unique functionalities. The clarification of the magnetoresistive properties and its correlation to the underlying magnetic configurations is essential for 2D vdW-based spintronic devices. Here, the effect of Co-doping on the magnetic and magnetotransport properties of Fe3GeTe2 have been investigated. Magnetotransport measurements reveal an unusual Hall effect behavior whose strength was considerably modified by Co-doping and attributed to arise from the underlying complicated spin textures. The present results provide a clue to tailoring of the underlying interactions necessary for the realization of a variety of unconventional spin textures for 2D vdW FM-based spintronics.
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17
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Zeng X, Huang S, Ye Q, Rajagopalan P, Li W, Kuang H, Ye G, Chen C, Li M, Liu Y, Shi L, Guo Y, Lu X, Shi W, Luo J, Wang X. Controllable high-performance memristors based on 2D Fe 2GeTe 3oxide for biological synapse imitation. NANOTECHNOLOGY 2021; 32:325205. [PMID: 33930891 DOI: 10.1088/1361-6528/abfd58] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Memristors are an important component of the next-generation artificial neural network, high computing systems, etc. In the past, two-dimensional materials based memristors have achieved a high performance and low power consumption, though one at the cost of the other. Furthermore, their performance can not be modulated frequently once their structures are fixed, which remains the bottleneck in the development. Herein, a series of forming free memristors are fabricated with the same Cu/Fe3GeTe2oxide/Fe3GeTe2/Al structure, yet the On/Off ratio and set voltage is modulated continuously by varying the oxidation time during fabrication. With an optimal oxidation time, a large On/Off ratio (1.58 × 103) and low set voltage (0.74 V) is achieved in a single device. The formation and rapture of Al conductive filaments are found to be responsible for the memristors, and the filaments density and the cross-section area increase with the increase of current compliance, which achieves a higher On/Off ratio. The memristor can imitate basic biological synaptic functions using voltage pulses, demonstrating the potential for low-power consuming neuromorphic computing applications.
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Affiliation(s)
- Xiangyu Zeng
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Shuyi Huang
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Qikai Ye
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Pandey Rajagopalan
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Wei Li
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Haoze Kuang
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Ge Ye
- Center for correlated matter and Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Chufan Chen
- Center for correlated matter and Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Menglu Li
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Yulu Liu
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Lin Shi
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Yuzheng Guo
- School of Electrical Engineering and Automation, Wuhan University, Wuhan 430072, People's Republic of China
| | - Xin Lu
- Center for correlated matter and Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Wenhua Shi
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, People's Republic of China
| | - Jikui Luo
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
| | - Xiaozhi Wang
- College of Information Science and Electronic Engineering, Hangzhou 310027, People's Republic of China
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18
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Hopkinson DG, Seki T, Clark N, Chen R, Zou Y, Kimura A, Gorbachev RV, Thomson T, Shibata N, Haigh SJ. Nanometre imaging of Fe 3GeTe 2 ferromagnetic domain walls. NANOTECHNOLOGY 2021; 32:205703. [PMID: 33624615 DOI: 10.1088/1361-6528/abe32b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Fe3GeTe2 is a layered crystal which has recently been shown to maintain its itinerant ferromagnetic properties even when atomically thin. Here, differential phase contrast scanning transmission electron microscopy is used to investigate the domain structure in a Fe3GeTe2 cross-sectional lamella at temperatures ranging from 95 to 250 K and at nanometre spatial resolution. Below the experimentally determined Curie temperature (T C) of 191 K, stripe domains magnetised along 〈0001〉, bounded with 180◦ Bloch type domain walls, are observed, transitioning to mixed Bloch-Néel type where the cross-sectional thickness is reduced below 50 nm. When warming towards T C, these domains undergo slight restructuring towards uniform size, before abruptly fading at T C. Localised loss of ferromagnetic order is seen over time, hypothesised to be a frustration of ferromagnetic order from ambient oxidation and basal cracking, which could enable selective modification of the magnetic properties for device applications.
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Affiliation(s)
- David G Hopkinson
- National Graphene Institute, The University of Manchester, M13 9PL, United Kingdom
- Department of Materials, The University of Manchester, M13 9PL, United Kingdom
| | - Takehito Seki
- Institute of Engineering Innovation, The University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
| | - Nicholas Clark
- National Graphene Institute, The University of Manchester, M13 9PL, United Kingdom
- Department of Materials, The University of Manchester, M13 9PL, United Kingdom
| | - Runze Chen
- Department of Computer Science, The University of Manchester, M13 9PL, United Kingdom
| | - Yichao Zou
- Department of Materials, The University of Manchester, M13 9PL, United Kingdom
| | - Ayumi Kimura
- Institute of Engineering Innovation, The University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
| | - Roman V Gorbachev
- National Graphene Institute, The University of Manchester, M13 9PL, United Kingdom
- Department of Physics & Astronomy, The University of Manchester, M13 9PL, United Kingdom
| | - Thomas Thomson
- Department of Computer Science, The University of Manchester, M13 9PL, United Kingdom
| | - Naoya Shibata
- Institute of Engineering Innovation, The University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
- Nanostructures Research Laboratory, Japan Fine Ceramic Center, Atsuta, Nagoya 456-8587, Japan
| | - Sarah J Haigh
- National Graphene Institute, The University of Manchester, M13 9PL, United Kingdom
- Department of Materials, The University of Manchester, M13 9PL, United Kingdom
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19
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Och M, Martin MB, Dlubak B, Seneor P, Mattevi C. Synthesis of emerging 2D layered magnetic materials. NANOSCALE 2021; 13:2157-2180. [PMID: 33475647 DOI: 10.1039/d0nr07867k] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
van der Waals atomically thin magnetic materials have been recently discovered. They have attracted enormous attention as they present unique magnetic properties, holding potential to tailor spin-based device properties and enable next generation data storage and communication devices. To fully understand the magnetism in two-dimensions, the synthesis of 2D materials over large areas with precise thickness control has to be accomplished. Here, we review the recent advancements in the synthesis of these materials spanning from metal halides, transition metal dichalcogenides, metal phosphosulphides, to ternary metal tellurides. We initially discuss the emerging device concepts based on magnetic van der Waals materials including what has been achieved with graphene. We then review the state of the art of the synthesis of these materials and we discuss the potential routes to achieve the synthesis of wafer-scale atomically thin magnetic materials. We discuss the synthetic achievements in relation to the structural characteristics of the materials and we scrutinise the physical properties of the precursors in relation to the synthesis conditions. We highlight the challenges related to the synthesis of 2D magnets and we provide a perspective for possible advancement of available synthesis methods to respond to the need for scalable production and high materials quality.
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Affiliation(s)
- Mauro Och
- Department of Materials, Imperial College London, SW72AZ London, UK.
| | - Marie-Blandine Martin
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Bruno Dlubak
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Pierre Seneor
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Cecilia Mattevi
- Department of Materials, Imperial College London, SW72AZ London, UK.
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Liu N, Gallaro CM, Shayan K, Mukherjee A, Kim B, Hone J, Vamivakas N, Strauf S. Antiferromagnetic proximity coupling between semiconductor quantum emitters in WSe 2 and van der Waals ferromagnets. NANOSCALE 2021; 13:832-841. [PMID: 33351877 DOI: 10.1039/d0nr06632j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
van der Waals ferromagnets have gained significant interest due to their unique ability to provide magnetic response even at the level of a few monolayers. Particularly in combination with 2D semiconductors, such as the transition metal dichalcogenide WSe2, one can create heterostructures that feature unique magneto-optical response in the exciton emission through the magnetic proximity effect. Here we use 0D quantum emitters in WSe2 to probe for the ferromagnetic response in heterostructures with Fe3GT and Fe5GT ferromagnets through an all-optical read-out technique that does not require electrodes. The spectrally narrow spin-doublet of the WSe2 quantum emitters allowed to fully resolve the hysteretic magneto-response in the exciton emission, revealing the characteristic signature of both ferro- and antiferromagnetic proximity coupling that originates from the interplay among Fe3GT or Fe5GT, a thin surface oxide, and the spin doublets of the quantum emitters. Our work highlights the utility of 0D quantum emitters for probing interface magnetic dipoles in vdW heterostructures with high precision. The observed hysteretic magneto response in the exciton emission of quantum emitters adds further new degrees of freedom for spin and g-factor manipulation of quantum states.
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Affiliation(s)
- Na Liu
- Department of Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA. and Center for Quantum Science and Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
| | - Cosmo M Gallaro
- Department of Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA. and Center for Quantum Science and Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
| | - Kamran Shayan
- The Institute of Optics, University of Rochester, Rochester, New York 14627, USA and Center for Coherence and Quantum Optics, University of Rochester, Rochester, New York 14627, USA
| | - Arunabh Mukherjee
- The Institute of Optics, University of Rochester, Rochester, New York 14627, USA and Center for Coherence and Quantum Optics, University of Rochester, Rochester, New York 14627, USA
| | - Bumho Kim
- Department of Mechanical Engineering, Columbia University, New York 10027, USA
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York 10027, USA
| | - Nick Vamivakas
- The Institute of Optics, University of Rochester, Rochester, New York 14627, USA and Center for Coherence and Quantum Optics, University of Rochester, Rochester, New York 14627, USA and Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - Stefan Strauf
- Department of Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA. and Center for Quantum Science and Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
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Wu Y, Zhang S, Zhang J, Wang W, Zhu YL, Hu J, Yin G, Wong K, Fang C, Wan C, Han X, Shao Q, Taniguchi T, Watanabe K, Zang J, Mao Z, Zhang X, Wang KL. Néel-type skyrmion in WTe 2/Fe 3GeTe 2 van der Waals heterostructure. Nat Commun 2020; 11:3860. [PMID: 32737289 PMCID: PMC7395126 DOI: 10.1038/s41467-020-17566-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 07/05/2020] [Indexed: 11/09/2022] Open
Abstract
The promise of high-density and low-energy-consumption devices motivates the search for layered structures that stabilize chiral spin textures such as topologically protected skyrmions. At the same time, recently discovered long-range intrinsic magnetic orders in the two-dimensional van der Waals materials provide a new platform for the discovery of novel physics and effects. Here we demonstrate the Dzyaloshinskii-Moriya interaction and Néel-type skyrmions are induced at the WTe2/Fe3GeTe2 interface. Transport measurements show the topological Hall effect in this heterostructure for temperatures below 100 K. Furthermore, Lorentz transmission electron microscopy is used to directly image Néel-type skyrmion lattice and the stripe-like magnetic domain structures as well. The interfacial coupling induced Dzyaloshinskii-Moriya interaction is estimated to have a large energy of 1.0 mJ m-2. This work paves a path towards the skyrmionic devices based on van der Waals layered heterostructures.
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Affiliation(s)
- Yingying Wu
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA
| | - Senfu Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Junwei Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Wei Wang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Yang Lin Zhu
- Department of Physics, Pennsylvania State University, University Park, PA, 16802, USA
| | - Jin Hu
- Department of Physics, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Gen Yin
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA
| | - Kin Wong
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA
| | - Chi Fang
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Caihua Wan
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiufeng Han
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Qiming Shao
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Jiadong Zang
- Department of Physics and Astronomy, University of New Hampshire, Durham, NH, 03824, USA
| | - Zhiqiang Mao
- Department of Physics, Pennsylvania State University, University Park, PA, 16802, USA
| | - Xixiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Kang L Wang
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA.
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