1
|
Cao Y, Cao A, Li S, Tang J, Hu R, Shang L, Li Y, Jiang K, Zhang J, Zhu L, Hu Z. Bias-dependent photoresponse of T d-WTe 2grown by chemical vapor deposition. NANOTECHNOLOGY 2024; 35:395201. [PMID: 38955161 DOI: 10.1088/1361-6528/ad5dbf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 07/02/2024] [Indexed: 07/04/2024]
Abstract
The type-II Weyl semimetal Td-WTe2is one of the wonder materials for high-performance optoelectronic devices. We report the self-powered Td-WTe2photodetectors and their bias-dependent photoresponse in the visible region (405, 520, 638 nm) driven by the bulk photovoltaic effect. The device shows the responsivity of 15.8 mAW-1and detectivity of 5.2 × 109Jones at 520 nm. Besides, the response time of the WTe2photodetector shows the strong bias-voltage dependent property. This work offers a physical reference for understanding the photoresponse process of Td-WTe2photodetectors.
Collapse
Affiliation(s)
- Yupeng Cao
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Aiping Cao
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Shubing Li
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Jianli Tang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Rui Hu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Liyan Shang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Yawei Li
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Kai Jiang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Jinzhong Zhang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Liangqing Zhu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Zhigao Hu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics and Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, People's Republic of China
| |
Collapse
|
2
|
Zhu S, Wu J, Zhu P, Pei C, Wang Q, Jia D, Wang X, Zhao Y, Gao L, Li C, Cao W, Zhang M, Zhang L, Li M, Gou H, Yang W, Sun J, Chen Y, Wang Z, Yao Y, Qi Y. Pressure-Induced Superconductivity and Topological Quantum Phase Transitions in the Topological Semimetal ZrTe 2. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301332. [PMID: 37944509 PMCID: PMC10724415 DOI: 10.1002/advs.202301332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 09/04/2023] [Indexed: 11/12/2023]
Abstract
Topological transition metal dichalcogenides (TMDCs) have attracted much attention due to their potential applications in spintronics and quantum computations. In this work, the structural and electronic properties of topological TMDCs candidate ZrTe2 are systematically investigated under high pressure. A pressure-induced Lifshitz transition is evidenced by the change of charge carrier type as well as the Fermi surface. Superconductivity is observed at around 8.3 GPa without structural phase transition. A typical dome-shape phase diagram is obtained with the maximum Tc of 5.6 K for ZrTe2 . Furthermore, the theoretical calculations suggest the presence of multiple pressure-induced topological quantum phase transitions, which coexists with emergence of superconductivity. The results demonstrate that ZrTe2 with nontrivial topology of electronic states displays new ground states upon compression.
Collapse
Affiliation(s)
- Shihao Zhu
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Juefei Wu
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Peng Zhu
- Centre for Quantum PhysicsKey Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE)School of PhysicsBeijing Institute of TechnologyBeijing100081China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic SystemsBeijing Institute of TechnologyBeijing100081China
- Material Science CenterYangtze Delta Region Academy of Beijing Institute of TechnologyJiaxing314011China
| | - Cuiying Pei
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Qi Wang
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
- ShanghaiTech Laboratory for Topological PhysicsShanghaiTech UniversityShanghai201210China
| | - Donghan Jia
- Center for High Pressure Science and Technology Advanced ResearchShanghai201203China
| | - Xinyu Wang
- Center for High Pressure Science and Technology Advanced ResearchShanghai201203China
| | - Yi Zhao
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Lingling Gao
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Changhua Li
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Weizheng Cao
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Mingxin Zhang
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Lili Zhang
- Shanghai Synchrotron Radiation FacilityShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201203China
| | - Mingtao Li
- Center for High Pressure Science and Technology Advanced ResearchShanghai201203China
| | - Huiyang Gou
- Center for High Pressure Science and Technology Advanced ResearchShanghai201203China
| | - Wenge Yang
- Center for High Pressure Science and Technology Advanced ResearchShanghai201203China
| | - Jian Sun
- National Laboratory of Solid State MicrostructuresSchool of Physics and Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210093China
| | - Yulin Chen
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
- ShanghaiTech Laboratory for Topological PhysicsShanghaiTech UniversityShanghai201210China
- Department of PhysicsClarendon LaboratoryUniversity of OxfordParks RoadOxfordOX1 3PUUK
| | - Zhiwei Wang
- Centre for Quantum PhysicsKey Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE)School of PhysicsBeijing Institute of TechnologyBeijing100081China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic SystemsBeijing Institute of TechnologyBeijing100081China
- Material Science CenterYangtze Delta Region Academy of Beijing Institute of TechnologyJiaxing314011China
| | - Yugui Yao
- Centre for Quantum PhysicsKey Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE)School of PhysicsBeijing Institute of TechnologyBeijing100081China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic SystemsBeijing Institute of TechnologyBeijing100081China
| | - Yanpeng Qi
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
- ShanghaiTech Laboratory for Topological PhysicsShanghaiTech UniversityShanghai201210China
- Shanghai Key Laboratory of High‐resolution Electron MicroscopyShanghaiTech UniversityShanghai201210China
| |
Collapse
|
3
|
Mandal M, Drucker NC, Siriviboon P, Nguyen T, Boonkird A, Lamichhane TN, Okabe R, Chotrattanapituk A, Li M. Topological Superconductors from a Materials Perspective. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:6184-6200. [PMID: 37637011 PMCID: PMC10448998 DOI: 10.1021/acs.chemmater.3c00713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/12/2023] [Indexed: 08/29/2023]
Abstract
Topological superconductors (TSCs) have garnered significant research and industry attention in the past two decades. By hosting Majorana bound states which can be used as qubits that are robust against local perturbations, TSCs offer a promising platform toward (nonuniversal) topological quantum computation. However, there has been a scarcity of TSC candidates, and the experimental signatures that identify a TSC are often elusive. In this Perspective, after a short review of the TSC basics and theories, we provide an overview of the TSC materials candidates, including natural compounds and synthetic material systems. We further introduce various experimental techniques to probe TSCs, focusing on how a system is identified as a TSC candidate and why a conclusive answer is often challenging to draw. We conclude by calling for new experimental signatures and stronger computational support to accelerate the search for new TSC candidates.
Collapse
Affiliation(s)
- Manasi Mandal
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Nathan C. Drucker
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- School
of Engineering and Applied Sciences, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Phum Siriviboon
- Department
of Physics, MIT, Cambridge, Massachusetts 02139, United States
| | - Thanh Nguyen
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Artittaya Boonkird
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Tej Nath Lamichhane
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Ryotaro Okabe
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Chemistry, MIT, Cambridge, Massachusetts 02139, United States
| | - Abhijatmedhi Chotrattanapituk
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Electrical Engineering and Computer Science, MIT, Cambridge, Massachusetts 02139, United States
| | - Mingda Li
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
4
|
Nobin MNM, Khan M, Islam SS, Ali ML. Pressure-induced physical properties in topological semi-metal TaM 2 (M = As, Sb). RSC Adv 2023; 13:22088-22100. [PMID: 37492517 PMCID: PMC10363775 DOI: 10.1039/d3ra03085g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/13/2023] [Indexed: 07/27/2023] Open
Abstract
In this study, DFT based first principles calculations are used for measuring the structural, elastic, mechanical, electronic, optical and thermodynamic features of topological semimetal TaM2 (M = As, Sb) under various pressures. We conducted the first investigation into the physical properties of the topological semimetal TaM2 (M = As, Sb) under pressure. Formation energy and Born stability criteria justify the compound's thermodynamic and mechanical stability. We used elastic constants, elastic moduli, Kleinman parameter, machinability index, and Vickers hardness to investigate the mechanical properties of topological semimetal TaM2. Poisson's and Pugh's ratios reveal that both compounds change from brittle to ductile in response to pressure. The increasing nature of elastic moduli suggests that TaM2 becomes stiffer under stress. The pressure has a significant effect on the anisotropy factor for both materials. Band structure analysis shows that both compounds are Weyl semi-metals and the d orbital contributes significantly to the formation of the Fermi level, as shown by the density of states (DOS) analysis. Investigation of electronic characteristics provides important support for dissecting optical performance. Both the reflectivity and absorption spectra shift upwards in energy when pressure is increased. The refractive index value decreases and becomes flat in the higher energy region. Based on their refractive indices, both of these materials demonstrate as a high-density optical data storage medium when exposed to the right light source. The thermodynamic properties including sound velocity, and Debye temperature all exhibit an increasing nature with applied pressure. Due to their high Debye temperatures, the components under study have a rather high melting point.
Collapse
Affiliation(s)
| | - Mithun Khan
- Department of Physics, Pabna University of Science and Technology Pabna-6600 Bangladesh
| | - Syed Saiful Islam
- Department of Physics, Pabna University of Science and Technology Pabna-6600 Bangladesh
| | - Md Lokman Ali
- Department of Physics, Pabna University of Science and Technology Pabna-6600 Bangladesh
| |
Collapse
|
5
|
Fang M, Liu X, Liu J, Chen Y, Su Y, Wei Y, Zhou Y, Peng G, Cai W, Deng C, Zhang XA. Improved Thermal Anisotropy of Multi-Layer Tungsten Telluride on Silicon Substrate. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1817. [PMID: 37368247 DOI: 10.3390/nano13121817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 05/25/2023] [Accepted: 06/03/2023] [Indexed: 06/28/2023]
Abstract
WTe2, a low-symmetry transition metal dichalcogenide, has broad prospects in functional device applications due to its excellent physical properties. When WTe2 flake is integrated into practical device structures, its anisotropic thermal transport could be affected greatly by the substrate, which matters a lot to the energy efficiency and functional performance of the device. To investigate the effect of SiO2/Si substrate, we carried out a comparative Raman thermometry study on a 50 nm-thick supported WTe2 flake (with κzigzag = 62.17 W·m-1·K-1 and κarmchair = 32.93 W·m-1·K-1), and a suspended WTe2 flake of similar thickness (with κzigzag = 4.45 W·m-1·K-1, κarmchair = 4.10 W·m-1·K-1). The results show that the thermal anisotropy ratio of supported WTe2 flake (κzigzag/κarmchair ≈ 1.89) is about 1.7 times that of suspended WTe2 flake (κzigzag/κarmchair ≈ 1.09). Based on the low symmetry nature of the WTe2 structure, it is speculated that the factors contributing to thermal conductivity (mechanical properties and anisotropic low-frequency phonons) may have affected the thermal conductivity of WTe2 flake in an uneven manner when supported on a substrate. Our findings could contribute to the 2D anisotropy physics and thermal transport study of functional devices based on WTe2 and other low-symmetry materials, which helps solve the heat dissipation problem and optimize thermal/thermoelectric performance for practical electronic devices.
Collapse
Affiliation(s)
- Mengke Fang
- College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
- College of Science, National University of Defense Technology, Changsha 410073, China
| | - Xiao Liu
- College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
- College of Science, National University of Defense Technology, Changsha 410073, China
| | - Jinxin Liu
- College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
- College of Science, National University of Defense Technology, Changsha 410073, China
| | - Yangbo Chen
- College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
| | - Yue Su
- College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
- College of Science, National University of Defense Technology, Changsha 410073, China
| | - Yuehua Wei
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
| | - Yuquan Zhou
- College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
| | - Gang Peng
- College of Science, National University of Defense Technology, Changsha 410073, China
| | - Weiwei Cai
- College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang 332105, China
| | - Chuyun Deng
- College of Science, National University of Defense Technology, Changsha 410073, China
| | - Xue-Ao Zhang
- College of Physical Science and Technology, Xiamen University, Xiamen 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang 332105, China
| |
Collapse
|
6
|
Zhang Y, Fei F, Liu R, Zhu T, Chen B, Qiu T, Zuo Z, Guo J, Tang W, Zhou L, Xi X, Wu X, Wu D, Zhong Z, Song F, Zhang R, Wang X. Enhanced Superconductivity and Upper Critical Field in Ta-Doped Weyl Semimetal T d -MoTe 2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207841. [PMID: 36905678 DOI: 10.1002/adma.202207841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 02/14/2023] [Indexed: 05/12/2023]
Abstract
2D transition metal dichalcogenides are promising platforms for next-generation electronics and spintronics. The layered Weyl semimetal (W,Mo)Te2 series features structural phase transition, nonsaturated magnetoresistance, superconductivity, and exotic topological physics. However, the superconducting critical temperature of the bulk (W,Mo)Te2 remains ultralow without applying a high pressure. Here, the significantly enhanced superconductivity is observed with a transition temperature as large as about 7.5 K in bulk Mo1- x Tax Te2 single crystals upon Ta doping (0 ≤ x ≤ 0.22), which is attributed to an enrichment of density of states at the Fermi level. In addition, an enhanced perpendicular upper critical field of 14.5 T exceeding the Pauli limit is also observed in Td -phase Mo1- x Tax Te2 (x = 0.08), indicating the possible emergence of unconventional mixed singlet-triplet superconductivity owing to the inversion symmetry breaking. This work provides a new pathway for exploring the exotic superconductivity and topological physics in transition metal dichalcogenides.
Collapse
Affiliation(s)
- Yong Zhang
- 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, China
| | - Fucong Fei
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, 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, China
| | - Tongshuai Zhu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Bo Chen
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Tianyu Qiu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Zewen Zuo
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Jingwen Guo
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Wenchao Tang
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Lifan Zhou
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Xiaoxiang Xi
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Xiaoshan Wu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Di Wu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Zhicheng Zhong
- Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo, 315201, China
| | - Fengqi Song
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Rong Zhang
- 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, China
- Department of Physics, Xiamen University, Xiamen, 316005, 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, China
| |
Collapse
|
7
|
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
|
8
|
Tang L, Mao Z, Wang C, Fu Q, Wang C, Zhang Y, Shen J, Yin Y, Shen B, Tan D, Li Q, Wang Y, Medhekar NV, Wu J, Yuan H, Li Y, Fuhrer MS, Zheng C. Giant piezoresistivity in a van der Waals material induced by intralayer atomic motions. Nat Commun 2023; 14:1519. [PMID: 36934098 PMCID: PMC10024745 DOI: 10.1038/s41467-023-37239-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 03/07/2023] [Indexed: 03/20/2023] Open
Abstract
The presence of the van der Waals gap in layered materials creates a wealth of intriguing phenomena different to their counterparts in conventional materials. For example, pressurization can generate a large anisotropic lattice shrinkage along the stacking orientation and/or a significant interlayer sliding, and many of the exotic pressure-dependent properties derive from these mechanisms. Here we report a giant piezoresistivity in pressurized β'-In2Se3. Upon compression, a six-orders-of-magnitude drop of electrical resistivity is obtained below 1.2 GPa in β'-In2Se3 flakes, yielding a giant piezoresistive gauge πp of -5.33 GPa-1. Simultaneously, the sample undergoes a semiconductor-to-semimetal transition without a structural phase transition. Surprisingly, linear dichroism study and theoretical first principles modelling show that these phenomena arise not due to shrinkage or sliding at the van der Waals gap, but rather are dominated by the layer-dependent atomic motions inside the quintuple layer, mainly from the shifting of middle Se atoms to their high-symmetric location. The atomic motions link to both the band structure modulation and the in-plane ferroelectric dipoles. Our work not only provides a prominent piezoresistive material but also points out the importance of intralayer atomic motions beyond van der Waals gap.
Collapse
Affiliation(s)
- Lingyun Tang
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou, Guangdong, 510641, China
| | - Zhongquan Mao
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou, Guangdong, 510641, China
| | - Chutian Wang
- Department of Materials Science and Engineering, & ARC Centre of Excellence in Future Low Energy Electronics Technologies, Monash University, Clayton, VIC, Australia
| | - Qi Fu
- Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou, 310024, Zhejiang Province, China
| | - Chen Wang
- Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou, 310024, Zhejiang Province, China
| | - Yichi Zhang
- Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou, 310024, Zhejiang Province, China
| | - Jingyi Shen
- Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou, 310024, Zhejiang Province, China
| | - Yuefeng Yin
- Department of Materials Science and Engineering, & ARC Centre of Excellence in Future Low Energy Electronics Technologies, Monash University, Clayton, VIC, Australia
| | - Bin Shen
- Center for Correlated Matter and Department of Physics, Zhejiang University, Hangzhou, China
| | - Dayong Tan
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640, Guangzhou, Guangdong, China
| | - Qian Li
- Shandong Key Laboratory of Optical Communication Science and Technology, School of Physics Science and Information Technology, Liaocheng University, Liaocheng, 252000, China
| | - Yonggang Wang
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing, 100094, China
| | - Nikhil V Medhekar
- Department of Materials Science and Engineering, & ARC Centre of Excellence in Future Low Energy Electronics Technologies, Monash University, Clayton, VIC, Australia
| | - Jie Wu
- Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou, 310024, Zhejiang Province, China
| | - Huiqiu Yuan
- Center for Correlated Matter and Department of Physics, Zhejiang University, Hangzhou, China
| | - Yanchun Li
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
| | - Michael S Fuhrer
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, & School of Physics and Astronomy, Monash University, Melbourne, VIC, 3800, Australia.
| | - Changxi Zheng
- Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou, 310024, Zhejiang Province, China.
| |
Collapse
|
9
|
Gao W, Zhu M, Chen D, Liang X, Wu Y, Zhu A, Han Y, Li L, Liu X, Zheng G, Lu W, Tian M. Evidences of Topological Surface States in the Nodal-Line Semimetal SnTaS 2 Nanoflakes. ACS NANO 2023; 17:4913-4921. [PMID: 36802534 DOI: 10.1021/acsnano.2c11932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Exploring the topological surface state of a topological semimetal by the transport technique has always been a big challenge because of the overwhelming contribution of the bulk state. In this work, we perform systematic angular-dependent magnetotransport measurements and electronic band calculations on SnTaS2 crystals, a layered topological nodal-line semimetal. Distinct Shubnikov-de Haas quantum oscillations were observed only in SnTaS2 nanoflakes when the thickness was below about 110 nm, and the oscillation amplitudes increased significantly with decreasing thickness. By analysis of the oscillation spectra, together with the theoretical calculation, a two-dimensional and topological nontrivial nature of the surface band is unambiguously identified, providing direct transport evidence of drumhead surface state for SnTaS2. Our comprehensive understanding of the Fermi surface topology of the centrosymmetric superconductor SnTaS2 is crucial for further research on the interplay of superconductivity and nontrivial topology.
Collapse
Affiliation(s)
- Wenshuai Gao
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Mengcheng Zhu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Dong Chen
- College of Physics, Qingdao University, Qingdao 266071, China
| | - Xin Liang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Yuelong Wu
- College of Physics, Qingdao University, Qingdao 266071, China
| | - Ankang Zhu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Yuyan Han
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Liang Li
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Xue Liu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Guolin Zheng
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Wenjian Lu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Mingliang Tian
- School of Physics and Optoelectronics Engineering, Anhui University, Hefei 230601, China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| |
Collapse
|
10
|
Kanchanavatee N, Ektarawong A, Pakornchote T, Alling B, Hodak S, Bovornratanaraks T. Phase transitions and suppression of magnetoresistance in WTe2-xSe xsystem. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:435403. [PMID: 35985303 DOI: 10.1088/1361-648x/ac8b53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
X-ray diffraction, Raman spectroscopy, and electrical resistivity measurements on polycrystalline WTe2-xSex(0 ⩽ x ⩽ 0.8) reveal aTd-1T'structural phase transition and suppression of magnetoresistance atx = 0.2. These phenomena are consistent with the pressure phase diagram of WTe2. However, chemical pressure due to substitution of smaller Se ion cannot generate pressure required for the phase transition. Strain induced by sample inhomogeneity is believed to be a trigger to the behaviors. In agreement with previous predictions and reports, a mixed phase of1T'and 2Hstructures was also detected in Se-rich samples. Coincidentally atx = 0.2, electrical resistivity analysis suggests a phase transition from a metallic phase to a nonmetallic phase that is possibly a topological-insulating phase.
Collapse
Affiliation(s)
- N Kanchanavatee
- Center of Excellence in Physics of Energy Materials, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - A Ektarawong
- Center of Excellence in Physics of Energy Materials, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Extreme Condition Physics Research Laboratory, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Thailand Center of Excellence in Physics, Ministry of Higher Education, Science, Research and Innovation, 328 Si Ayutthaya Road, Bangkok 10400, Thailand
- Chula Intelligent and Complex Systems, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - T Pakornchote
- Center of Excellence in Physics of Energy Materials, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Extreme Condition Physics Research Laboratory, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Thailand Center of Excellence in Physics, Ministry of Higher Education, Science, Research and Innovation, 328 Si Ayutthaya Road, Bangkok 10400, Thailand
| | - B Alling
- Theoretical Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden
| | - S Hodak
- Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - T Bovornratanaraks
- Center of Excellence in Physics of Energy Materials, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Extreme Condition Physics Research Laboratory, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Thailand Center of Excellence in Physics, Ministry of Higher Education, Science, Research and Innovation, 328 Si Ayutthaya Road, Bangkok 10400, Thailand
| |
Collapse
|
11
|
Ku CH, Liu X, Xie J, Zhang W, Lam ST, Chen Y, Zhou X, Zhao Y, Wang S, Yang S, Lai KT, Goh SK. Patterned diamond anvils prepared via laser writing for electrical transport measurements of thin quantum materials under pressure. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:083912. [PMID: 36050123 DOI: 10.1063/5.0098226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Quantum materials exhibit intriguing properties with important scientific values and huge technological potential. Electrical transport measurements under hydrostatic pressure have been influential in unraveling the underlying physics of many quantum materials in bulk form. However, such measurements have not been applied widely to samples in the form of thin flakes, in which new phenomena can emerge, due to the difficulty in attaching fine wires to a thin sample suitable for high-pressure devices. Here, we utilize a home-built direct laser writing system to functionalize a diamond anvil to directly integrate the capability of conducting electrical transport measurements of thin flakes with a pressure cell. With our methodology, the culet of a diamond anvil is equipped with a set of custom-designed conducting tracks. We demonstrate the superiority of these tracks as electrodes for the studies of thin flakes by presenting the measurement of pressure-enhanced superconductivity and quantum oscillations in a flake of MoTe2.
Collapse
Affiliation(s)
- Che-Hsuan Ku
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Xinyou Liu
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Jianyu Xie
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - W Zhang
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Siu Tung Lam
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Y Chen
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Xuefeng Zhou
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yusheng Zhao
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Shanmin Wang
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Sen Yang
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Kwing To Lai
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Swee K Goh
- Department of Physics, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| |
Collapse
|
12
|
Ozdemir I, Holleitner AW, Kastl C, Aktürk OÜ. Thickness and defect dependent electronic, optical and thermoelectric features of [Formula: see text]. Sci Rep 2022; 12:12756. [PMID: 35882909 PMCID: PMC9325696 DOI: 10.1038/s41598-022-16899-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/18/2022] [Indexed: 11/08/2022] Open
Abstract
Transition metal dichalcogenides (TMDs) receive significant attention due to their outstanding electronic and optical properties. In this study, we investigate the electronic, optical, and thermoelectric properties of single and few layer [Formula: see text] in detail utilizing first-principles methods based on the density functional theory (DFT). Within the scope of both PBE and HSE06 including spin orbit coupling (SOC), the simulations predict the electronic band gap values to decrease as the number of layers increases. Moreover, spin-polarized DFT calculations combined with the semi-classical Boltzmann transport theory are applied to estimate the anisotropic thermoelectric power factor (Seebeck coefficient, S) for [Formula: see text] in both the monolayer and multilayer limit, and S is obtained below the optimal value for practical applications. The optical absorbance of [Formula: see text] monolayer is obtained to be slightly less than the values reported in literature for 2H TMD monolayers of [Formula: see text], [Formula: see text], and [Formula: see text]. Furthermore, we simulate the impact of defects, such as vacancy, antisite and substitution defects, on the electronic, optical and thermoelectric properties of monolayer [Formula: see text]. Particularly, the Te-[Formula: see text] substitution defect in parallel orientation yields negative formation energy, indicating that the relevant defect may form spontaneously under relevant experimental conditions. We reveal that the electronic band structure of [Formula: see text] monolayer is significantly influenced by the presence of the considered defects. According to the calculated band gap values, a lowering of the conduction band minimum gives rise to metallic characteristics to the structure for the single Te(1) vacancy, a diagonal Te line defect, and the Te(1)-[Formula: see text] substitution, while the other investigated defects cause an opening of a small positive band gap at the Fermi level. Consequently, the real ([Formula: see text]) and imaginary ([Formula: see text]) parts of the dielectric constant at low frequencies are very sensitive to the applied defects, whereas we find that the absorbance (A) at optical frequencies is less significantly affected. We also predict that certain point defects can enhance the otherwise moderate value of S in pristine [Formula: see text] to values relevant for thermoelectric applications. The described [Formula: see text] monolayers, as functionalized with the considered defects, offer the possibility to be applied in optical, electronic, and thermoelectric devices.
Collapse
Affiliation(s)
- Ilkay Ozdemir
- Physics Department, Adnan Menderes University, 09100 Aydin, Turkey
| | - Alexander W. Holleitner
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center of Quantum Science and Technology (MCQST), Schellingstr. 4, 80799 Munich, Germany
| | - Christoph Kastl
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center of Quantum Science and Technology (MCQST), Schellingstr. 4, 80799 Munich, Germany
| | - Olcay Üzengi Aktürk
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Electrical Electronics Engineering Department, Adnan Menderes University, 09100 Aydin, Turkey
| |
Collapse
|
13
|
Zhou Y, An C, Chen X, Zhou Y, Fang Y, Zhang Z, Yang Z. Pressure evolution of electronic and structural properties in transition metal dichalcogenide 1 T-Co 1.06Te 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:315704. [PMID: 35636404 DOI: 10.1088/1361-648x/ac7495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Two-dimensional transition metal dichalcogenides (TMDs) are important materials for promising electronic devices because they usually exhibit excellent and highly tunable electronic properties. Here, we report on the pressure-driven electronic phase transition in a TMD 1T-Co1.06Te2. High-pressure transport measurements reveal a sign reversal of the Hall coefficients at a critical point ofPC∼ 32 GPa, evidencing a transition from hole band(s) dominated transport into one that is dominated by electron band(s). Synchrotron x-ray diffraction experiments demonstrate that no structural phase transition occurs below 46.3 GPa, indicating an electronic origin of the transition. Moreover, a kink anomaly of the lattice constant ratioc/ais also observed atP=PC. These results might indicate a Lifshitz transition which refers to a change of Fermi surface topology in absence of structural transition.
Collapse
Affiliation(s)
- Ying Zhou
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, People's Republic of China
| | - Chao An
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, People's Republic of China
| | - Xuliang Chen
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- High Magnetic Field Laboratory of Anhui Province, Hefei 230031, People's Republic of China
| | - Yonghui Zhou
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- High Magnetic Field Laboratory of Anhui Province, Hefei 230031, People's Republic of China
| | - Yong Fang
- Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500, People's Republic of China
| | - Zhitao Zhang
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- High Magnetic Field Laboratory of Anhui Province, Hefei 230031, People's Republic of China
| | - Zhaorong Yang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, People's Republic of China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- High Magnetic Field Laboratory of Anhui Province, Hefei 230031, People's Republic of China
| |
Collapse
|
14
|
Wang M, Kumar A, Dong H, Woods JM, Pondick JV, Xu S, Hynek DJ, Guo P, Qiu DY, Cha JJ. A Gapped Phase in Semimetallic T d -WTe 2 Induced by Lithium Intercalation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2200861. [PMID: 35488783 DOI: 10.1002/adma.202200861] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/20/2022] [Indexed: 06/14/2023]
Abstract
The Weyl semimetal WTe2 has shown several correlated electronic behaviors, such as the quantum spin Hall effect, superconductivity, ferroelectricity, and a possible exciton insulator state, all of which can be tuned by various physical and chemical approaches. Here, a new electronic phase in WTe2 induced by lithium intercalation is discovered. The new phase exhibits an increasing resistivity with decreasing temperature and its carrier density is almost two orders of magnitude lower than the carrier density of the semimetallic Td phase, probed by in situ Hall measurements as a function of lithium intercalation. The theoretical calculations predict the new lithiated phase to be a potential charge density wave (CDW) phase with a bandgap of ≈0.14 eV, in good agreement with the in situ transport data. The new phase is structurally distinct from the initial Td phase, characterized by polarization-angle-dependent Raman spectroscopy, and large lattice distortions close to 6% are predicted in the new phase. This finding of a new gapped phase in a 2D semimetal demonstrates electrochemical intercalation as a powerful tuning knob for modulating electron density and phase stability in 2D materials.
Collapse
Affiliation(s)
- Mengjing Wang
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
| | - Aakash Kumar
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
| | - Hao Dong
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, 06511, USA
| | - John M Woods
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
| | - Joshua V Pondick
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
| | - Shiyu Xu
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
| | - David J Hynek
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
| | - Peijun Guo
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, 06511, USA
| | - Diana Y Qiu
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
| | - Judy J Cha
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
- Energy Sciences Institute, Yale West Campus, West Haven, CT, 06516, USA
| |
Collapse
|
15
|
A new class of bilayer kagome lattice compounds with Dirac nodal lines and pressure-induced superconductivity. Nat Commun 2022; 13:2773. [PMID: 35589799 PMCID: PMC9120444 DOI: 10.1038/s41467-022-30442-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 04/27/2022] [Indexed: 11/08/2022] Open
Abstract
Kagome lattice composed of transition-metal ions provides a great opportunity to explore the intertwining between geometry, electronic orders and band topology. The discovery of multiple competing orders that connect intimately with the underlying topological band structure in nonmagnetic kagome metals AV3Sb5 (A = K, Rb, Cs) further pushes this topic to the quantum frontier. Here we report a new class of vanadium-based compounds with kagome bilayers, namely AV6Sb6 (A = K, Rb, Cs) and V6Sb4, which, together with AV3Sb5, compose a series of kagome compounds with a generic chemical formula (Am-1Sb2m)(V3Sb)n (m = 1, 2; n = 1, 2). Theoretical calculations combined with angle-resolved photoemission measurements reveal that these compounds feature Dirac nodal lines in close vicinity to the Fermi level. Pressure-induced superconductivity in AV6Sb6 further suggests promising emergent phenomena in these materials. The establishment of a new family of layered kagome materials paves the way for designer of fascinating kagome systems with diverse topological nontrivialities and collective ground states.
Collapse
|
16
|
Zhou R, Wu J, Chen Y, Xie L. Polymorph Structures, Rich Physical Properties and Potential Applications of
Two‐Dimensional MoTe
2
,
WTe
2
and Its Alloys. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202100777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Rui Zhou
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Juanxia Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology Beijing 100190 China
| | - Yuansha Chen
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics, Chinese Academy of Sciences Beijing 100190 China
| | - Liming Xie
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| |
Collapse
|
17
|
Jin M, Yu P, Fan C, Li Q, Kong P, Shen Z, Qin X, Chi Z, Jin C, Liu G, Zhong G, Xu G, Liu Z, Zhu J. Discovery of Dome-Shaped Superconducting Phase and Anisotropic Transport in a van der Waals Layered Candidate NbIrTe 4 under Pressure. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2103250. [PMID: 34723437 PMCID: PMC8693038 DOI: 10.1002/advs.202103250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/26/2021] [Indexed: 06/13/2023]
Abstract
The unique electronic structure and crystal structure driven by external pressure in transition metal tellurides (TMTs) can host unconventional quantum states. Here, the discovery of pressure-induced phase transition at ≈2 GPa, and dome-shaped superconducting phase emerged in van der Waals layered NbIrTe4 is reported. The highest critical temperature (Tc ) is ≈5.8 K at pressure of ≈16 GPa, where the interlayered Te-Te covalent bonds form simultaneously derived from the synchrotron diffraction data, indicating the hosting structure of superconducting evolved from low-pressure two-dimensional (2D) phase to three-dimensional (3D) structure with pressure higher than 30 GPa. Strikingly, the authors have found an anisotropic transport in the vicinity of the superconducting state, suggesting the emergence of a "stripe"-like phase. The dome-shaped superconducting phase and anisotropic transport are possibly due to the spatial modulation of interlayer Josephson coupling .
Collapse
Affiliation(s)
- Meiling Jin
- Department of Physics and Shenzhen Engineering Research Center for Frontier Materials Synthesis at High PressuresSouthern University of Science and Technology (SUSTech)Shenzhen518055China
- Center for High Pressure Science and Technology Advanced Research (HPSTAR)Beijing100094China
| | - Peng Yu
- State Key Laboratory of Optoelectronic Materials and TechnologiesSchool of Materials Science and EngineeringSun Yat‐sen UniversityGuangzhou510275China
| | - Changzeng Fan
- State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao066004China
| | - Qiang Li
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Panlong Kong
- Center for High Pressure Science and Technology Advanced Research (HPSTAR)Beijing100094China
| | - Zhiwei Shen
- State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao066004China
| | - Xiaomei Qin
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Zhenhua Chi
- Institute of High Pressure PhysicsSchool of Physical Science and TechnologyNingbo UniversityNingbo315211China
| | - Changqing Jin
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesSchool of Physical SciencesUniversity of Chinese Academy of SciencesBeijing100190China
| | - Guangtong Liu
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesSchool of Physical SciencesUniversity of Chinese Academy of SciencesBeijing100190China
| | - Guyue Zhong
- Wuhan National High Magnetic Field Center and School of PhysicsHuazhong University of Science and TechnologyWuhan430074China
| | - Gang Xu
- Wuhan National High Magnetic Field Center and School of PhysicsHuazhong University of Science and TechnologyWuhan430074China
| | - Zheng Liu
- School of Materials Science and EngineeringNanyang Technological University50 Nanyang AvenueSingapore639798Singapore
- School of Electrical and Electronic EngineeringNanyang Technological UniversitySingapore639798Singapore
| | - Jinlong Zhu
- Department of Physics and Shenzhen Engineering Research Center for Frontier Materials Synthesis at High PressuresSouthern University of Science and Technology (SUSTech)Shenzhen518055China
| |
Collapse
|
18
|
MoTe 2 Field-Effect Transistors with Low Contact Resistance through Phase Tuning by Laser Irradiation. NANOMATERIALS 2021; 11:nano11112805. [PMID: 34835570 PMCID: PMC8620056 DOI: 10.3390/nano11112805] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 11/17/2022]
Abstract
Due to their extraordinary electrical and physical properties, two-dimensional (2D) transition metal dichalcogenides (TMDs) are considered promising for use in next-generation electrical devices. However, the application of TMD-based devices is limited because of the Schottky barrier interface resulting from the absence of dangling bonds on the TMDs’ surface. Here, we introduce a facile phase-tuning approach for forming a homogenous interface between semiconducting hexagonal (2H) and semi-metallic monoclinic (1T′) molybdenum ditelluride (MoTe2). The formation of ohmic contacts increases the charge carrier mobility of MoTe2 field-effect transistor devices to 16.1 cm2 V−1s−1 with high reproducibility, while maintaining a high on/off current ratio by efficiently improving charge injection at the interface. The proposed method enables a simple fabrication process, local patterning, and large-area scaling for the creation of high-performance 2D electronic devices.
Collapse
|
19
|
Niu K, Weng M, Li S, Guo Z, Wang G, Han M, Pan F, Lin J. Direct Visualization of Large-Scale Intrinsic Atomic Lattice Structure and Its Collective Anisotropy in Air-Sensitive Monolayer 1T'- WTe 2. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2101563. [PMID: 34467674 PMCID: PMC8529427 DOI: 10.1002/advs.202101563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Probing large-scale intrinsic structure of air-sensitive 2D materials with atomic resolution is so far challenging due to their rapid oxidization and contamination. Here, by keeping the whole experiment including growth, transfer, and characterizations in an interconnected atmosphere-control environment, the large-scale intact lattice structure of air-sensitive monolayer 1T'-WTe2 is directly visualized by atom-resolved scanning transmission electron microscopy. Benefit from the large-scale atomic mapping, collective lattice distortions are further unveiled due to the presence of anisotropic rippling, which propagates perpendicular to only one of the preferential lattice planes in the same WTe2 monolayer. Such anisotropic lattice rippling modulates the intrinsic point defect (Te vacancy) distribution, in which they aggregate at the constrictive inner side of the undulating structure, presumably due to the ripple-induced asymmetric strain as elaborated by density functional theory. The results pave the way for atomic characterizations and defect engineering of air-sensitive 2D layered materials.
Collapse
Affiliation(s)
- Kangdi Niu
- Department of PhysicsSouthern University of Science and TechnologyShenzhen518055China
- Shenzhen Key Laboratory of Advanced Quantum Functional Materials and DevicesSouthern University of Science and TechnologyShenzhen518055China
| | - Mouyi Weng
- School of Advanced MaterialsPeking UniversityShenzhen Graduate SchoolShenzhen518055China
| | - Songge Li
- Department of PhysicsSouthern University of Science and TechnologyShenzhen518055China
| | - Zenglong Guo
- Department of PhysicsSouthern University of Science and TechnologyShenzhen518055China
| | - Gang Wang
- Department of PhysicsSouthern University of Science and TechnologyShenzhen518055China
| | - Mengjiao Han
- Department of PhysicsSouthern University of Science and TechnologyShenzhen518055China
- Shenzhen Key Laboratory of Advanced Quantum Functional Materials and DevicesSouthern University of Science and TechnologyShenzhen518055China
| | - Feng Pan
- School of Advanced MaterialsPeking UniversityShenzhen Graduate SchoolShenzhen518055China
| | - Junhao Lin
- Department of PhysicsSouthern University of Science and TechnologyShenzhen518055China
- Shenzhen Key Laboratory of Advanced Quantum Functional Materials and DevicesSouthern University of Science and TechnologyShenzhen518055China
| |
Collapse
|
20
|
Soares DM, Singh G. Weyl semimetal orthorhombic Td-WTe 2as an electrode material for sodium- and potassium-ion batteries. NANOTECHNOLOGY 2021; 32:505402. [PMID: 34488215 DOI: 10.1088/1361-6528/ac23f3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 09/06/2021] [Indexed: 06/13/2023]
Abstract
Alkali metals such as sodium and potassium have become promising candidates for the next generation of monovalent-ion batteries. However, a challenge for these battery technologies lies in the development of electrode materials that deliver high capacity and stable performance even at high cycling currents. Here we study orthorhombic tungsten ditelluride or Td-WTe2as an electrode material for sodium- (SIB) and potassium-ion batteries (KIB) in propylene carbonate (PC) based electrolyte. Results show that despite larger Shannon's radius of potassium-ions and their sluggish diffusion in Td-WTe2due to higher overpotential, at 100 mA.g-1KIB-half cells showed higher cycling stability and low capacity decay of 4% versus 16% compared to SIB-half cells. Likewise, in a rate capability test at 61stcycle (at 50 mA.g-1), the KIB-half cells yielded charge capacity of 172 mAh.g-1versus 137 mAh.g-1of SIB-half cells. The superior electrochemical performance of Td-WTe2electrode material in KIB-half cells is explained based on the concept of Stokes' radius-smaller desolvation activation energy resulted in higher mobility of potassium-ions in PC-based electrolyte. In addition, the likely mechanisms of electrochemical insertion and extraction of Na- and K-ions in Td-WTe2are also discussed.
Collapse
Affiliation(s)
- Davi Marcelo Soares
- Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS, 66506, United States of America
| | - Gurpreet Singh
- Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS, 66506, United States of America
| |
Collapse
|
21
|
Anisotropic Optical Response of WTe 2 Single Crystals Studied by Ellipsometric Analysis. NANOMATERIALS 2021; 11:nano11092262. [PMID: 34578578 PMCID: PMC8468096 DOI: 10.3390/nano11092262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/19/2021] [Accepted: 08/27/2021] [Indexed: 11/23/2022]
Abstract
In this paper we report the crystal growth conditions and optical anisotropy properties of Tungsten ditelluride (WTe2) single crystals. The chemical vapor transport (CVT) method was used for the synthesis of large WTe2 crystals with high crystallinity and surface quality. These were structurally and morphologically characterized by means of X-ray diffraction, optical profilometry and Raman spectroscopy. Through spectroscopic ellipsometry analysis, based on the Tauc–Lorentz model, we identified a high refractive index value (~4) and distinct tri-axial anisotropic behavior of the optical constants, which opens prospects for surface plasmon activity, revealed by the dielectric function. The anisotropic physical nature of WTe2 shows practical potential for low-loss light modulation at the 2D nanoscale level.
Collapse
|
22
|
Zhao L, Yi C, Wang CT, Chi Z, Yin Y, Ma X, Dai J, Yang P, Yue B, Cheng J, Hong F, Wang JT, Han Y, Shi Y, Yu X. Monoclinic EuSn_{2}As_{2}: A Novel High-Pressure Network Structure. PHYSICAL REVIEW LETTERS 2021; 126:155701. [PMID: 33929239 DOI: 10.1103/physrevlett.126.155701] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/07/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
The layered crystal of EuSn_{2}As_{2} has a Bi_{2}Te_{3}-type structure in rhombohedral (R3[over ¯]m) symmetry and has been confirmed to be an intrinsic magnetic topological insulator at ambient conditions. Combining ab initio calculations and in situ x-ray diffraction measurements, we identify a new monoclinic EuSn_{2}As_{2} structure in C2/m symmetry above ∼14 GPa. It has a three-dimensional network made up of honeycomblike Sn sheets and zigzag As chains, transformed from the layered EuSn_{2}As_{2} via a two-stage reconstruction mechanism with the connecting of Sn-Sn and As-As atoms successively between the buckled SnAs layers. Its dynamic structural stability has been verified by phonon mode analysis. Electrical resistance measurements reveal an insulator-metal-superconductor transition at low temperature around 5 and 15 GPa, respectively, according to the structural conversion, and the superconductivity with a T_{C} value of ∼4 K is observed up to 30.8 GPa. These results establish a high-pressure EuSn_{2}As_{2} phase with intriguing structural and electronic properties and expand our understandings about the layered magnetic topological insulators.
Collapse
Affiliation(s)
- Lin Zhao
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
| | - Changjiang Yi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Chang-Tian Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenhua Chi
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Yunyu Yin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoli Ma
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jianhong Dai
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Pengtao Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Binbin Yue
- Center for High Pressure Science & Technology Advanced Research, Haidian, Beijing 100094, China
| | - Jinguang Cheng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Fang Hong
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jian-Tao Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Yonghao Han
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaohui Yu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
23
|
Beaulieu S, Dong S, Tancogne-Dejean N, Dendzik M, Pincelli T, Maklar J, Xian RP, Sentef MA, Wolf M, Rubio A, Rettig L, Ernstorfer R. Ultrafast dynamical Lifshitz transition. SCIENCE ADVANCES 2021; 7:7/17/eabd9275. [PMID: 33883128 PMCID: PMC8059938 DOI: 10.1126/sciadv.abd9275] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 03/04/2021] [Indexed: 06/12/2023]
Abstract
Fermi surface is at the heart of our understanding of metals and strongly correlated many-body systems. An abrupt change in the Fermi surface topology, also called Lifshitz transition, can lead to the emergence of fascinating phenomena like colossal magnetoresistance and superconductivity. While Lifshitz transitions have been demonstrated for a broad range of materials by equilibrium tuning of macroscopic parameters such as strain, doping, pressure, and temperature, a nonequilibrium dynamical route toward ultrafast modification of the Fermi surface topology has not been experimentally demonstrated. Combining time-resolved multidimensional photoemission spectroscopy with state-of-the-art TDDFT+U simulations, we introduce a scheme for driving an ultrafast Lifshitz transition in the correlated type-II Weyl semimetal T d-MoTe2 We demonstrate that this nonequilibrium topological electronic transition finds its microscopic origin in the dynamical modification of the effective electronic correlations. These results shed light on a previously unexplored ultrafast scheme for controlling the Fermi surface topology in correlated quantum materials.
Collapse
Affiliation(s)
- Samuel Beaulieu
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany.
| | - Shuo Dong
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Nicolas Tancogne-Dejean
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg 22761, Germany.
| | - Maciej Dendzik
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
- Department of Applied Physics, KTH Royal Institute of Technology, Hannes Alfvéns väg 12, 114 19 Stockholm, Sweden
| | - Tommaso Pincelli
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Julian Maklar
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - R Patrick Xian
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Michael A Sentef
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Martin Wolf
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Angel Rubio
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg 22761, Germany
- Center for Computational Quantum Physics (CCQ), Flatiron Institute, 162 Fifth Avenue, New York, NY 10010, USA
| | - Laurenz Rettig
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Ralph Ernstorfer
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany.
| |
Collapse
|
24
|
Hynek DJ, Singhania RM, Xu S, Davis B, Wang L, Yarali M, Pondick JV, Woods JM, Strandwitz NC, Cha JJ. cm 2-Scale Synthesis of MoTe 2 Thin Films with Large Grains and Layer Control. ACS NANO 2021; 15:410-418. [PMID: 33211473 DOI: 10.1021/acsnano.0c08069] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Owing to the small energy differences between its polymorphs, MoTe2 can access a full spectrum of electronic states from the 2H semiconducting state to the 1T' semimetallic state and from the Td Weyl semimetallic state to the superconducting state in the 1T' and Td phase at low temperature. Thus, it is a model system for phase transformation studies as well as quantum phenomena such as the quantum spin Hall effect and topological superconductivity. Careful studies of MoTe2 and its potential applications require large-area MoTe2 thin films with high crystallinity and thickness control. Here, we present cm2-scale synthesis of 2H-MoTe2 thin films with layer control and large grains that span several microns. Layer control is achieved by controlling the initial thickness of the precursor MoOx thin films, which are deposited on sapphire substrates by atomic layer deposition and subsequently tellurized. Despite the van der Waals epitaxy, the precursor-substrate interface is found to critically determine the uniformity in thickness and grain size of the resulting MoTe2 films: MoTe2 grown on sapphire show uniform films while MoTe2 grown on amorphous SiO2 substrates form islands. This synthesis strategy decouples the layer control from the variabilities of growth conditions for robust growth results and is applicable to growing other transition-metal dichalcogenides with layer control.
Collapse
Affiliation(s)
- David J Hynek
- Energy Sciences Institute, Department of Mechanical Engineering and Materials Science, Yale University, West Haven, Connecticut 06516, United States
| | - Raivat M Singhania
- Department of Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Shiyu Xu
- Energy Sciences Institute, Department of Mechanical Engineering and Materials Science, Yale University, West Haven, Connecticut 06516, United States
| | - Benjamin Davis
- Department of Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Leizhi Wang
- Energy Sciences Institute, Department of Mechanical Engineering and Materials Science, Yale University, West Haven, Connecticut 06516, United States
| | - Milad Yarali
- Energy Sciences Institute, Department of Mechanical Engineering and Materials Science, Yale University, West Haven, Connecticut 06516, United States
| | - Joshua V Pondick
- Energy Sciences Institute, Department of Mechanical Engineering and Materials Science, Yale University, West Haven, Connecticut 06516, United States
| | - John M Woods
- Energy Sciences Institute, Department of Mechanical Engineering and Materials Science, Yale University, West Haven, Connecticut 06516, United States
| | - Nicholas C Strandwitz
- Department of Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Judy J Cha
- Energy Sciences Institute, Department of Mechanical Engineering and Materials Science, Yale University, West Haven, Connecticut 06516, United States
| |
Collapse
|
25
|
Mandal M, Singh RP. Emergent superconductivity by Re doping in type -II Weyl semimetal NiTe 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:135602. [PMID: 33406510 DOI: 10.1088/1361-648x/abd8f3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
Recently topological semimetals emerge as a new platform to realise topological superconductivity. Here we report the emergent superconductivity in single-crystals of Re doped type-II Weyl semimetal NiTe2. The magnetic and transport measurements highlight that Re substitution in Ni-site induces superconductivity at a maximum temperature of 2.36 K. Hall effect and specific heat measurements indicate that Re substitution is doping hole and facilitates the emergence of superconductivity by phonon softening and enhancing the electron-phonon coupling.
Collapse
Affiliation(s)
- Manasi Mandal
- Department of Physics, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, India
| | - R P Singh
- Department of Physics, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, India
| |
Collapse
|
26
|
Zhang L, Tang Y, Khan AR, Hasan MM, Wang P, Yan H, Yildirim T, Torres JF, Neupane GP, Zhang Y, Li Q, Lu Y. 2D Materials and Heterostructures at Extreme Pressure. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2002697. [PMID: 33344136 PMCID: PMC7740103 DOI: 10.1002/advs.202002697] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/03/2020] [Indexed: 06/02/2023]
Abstract
2D materials possess wide-tuning properties ranging from semiconducting and metallization to superconducting, etc., which are determined by their structure, empowering them to be appealing in optoelectronic and photovoltaic applications. Pressure is an effective and clean tool that allows modifications of the electronic structure, crystal structure, morphologies, and compositions of 2D materials through van der Waals (vdW) interaction engineering. This enables an insightful understanding of the variable vdW interaction induced structural changes, structure-property relations as well as contributes to the versatile implications of 2D materials. Here, the recent progress of high-pressure research toward 2D materials and heterostructures, involving graphene, boron nitride, transition metal dichalcogenides, 2D perovskites, black phosphorene, MXene, and covalent-organic frameworks, using diamond anvil cell is summarized. A detailed analysis of pressurized structure, phonon dynamics, superconducting, metallization, doping together with optical property is performed. Further, the pressure-induced optimized properties and potential applications as well as the vision of engineering the vdW interactions in heterostructures are highlighted. Finally, conclusions and outlook are presented on the way forward.
Collapse
Affiliation(s)
- Linglong Zhang
- Institute of Microscale OptoelectronicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Yilin Tang
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Ahmed Raza Khan
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Md Mehedi Hasan
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Ping Wang
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Han Yan
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Tanju Yildirim
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Juan Felipe Torres
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Guru Prakash Neupane
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Yupeng Zhang
- Institute of Microscale OptoelectronicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China
| | - Quan Li
- International Center for Computational Methods and SoftwareCollege of PhysicsJilin UniversityChangchun130012China
| | - Yuerui Lu
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| |
Collapse
|
27
|
Hsu YT, Cole WS, Zhang RX, Sau JD. Inversion-Protected Higher-Order Topological Superconductivity in Monolayer WTe_{2}. PHYSICAL REVIEW LETTERS 2020; 125:097001. [PMID: 32915630 DOI: 10.1103/physrevlett.125.097001] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
Monolayer WTe_{2}, a centrosymmetric transition metal dichacogenide, has recently been established as a quantum spin Hall insulator and found superconducting upon gating. Here we study the pairing symmetry and topological nature of superconducting WTe_{2} with a microscopic model at mean-field level. Surprisingly, we find that the spin-triplet phases in our phase diagram all host Majorana modes localized on two opposite corners. Even when the conventional pairing is favored, we find that an intermediate in-plane magnetic field exceeding the Pauli limit stabilizes an unconventional equal-spin pairing aligning with the field, which also hosts Majorana corner modes. Motivated by our findings, we obtain a recipe for two-dimensional superconductors featuring "higher-order topology" from the boundary perspective. Generally, a superconducting inversion-symmetric quantum spin Hall material whose normal-state Fermi surface is away from high-symmetry points, such as gated monolayer WTe_{2}, hosts Majorana corner modes if the superconductivity is parity-odd. We further point out that this higher-order phase is an inversion-protected topological crystalline superconductor and study the bulk-boundary correspondence. Finally, we discuss possible experiments for probing the Majorana corner modes. Our findings suggest superconducting monolayer WTe_{2} is a playground for higher-order topological superconductivity and possibly the first material realization for inversion-protected Majorana corner modes without utilizing proximity effect.
Collapse
Affiliation(s)
- Yi-Ting Hsu
- Condensed Matter Theory Center and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - William S Cole
- Condensed Matter Theory Center and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - Rui-Xing Zhang
- Condensed Matter Theory Center and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - Jay D Sau
- Condensed Matter Theory Center and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| |
Collapse
|
28
|
Yan Z, Wu Z, Huang W. Vortex End Majorana Zero Modes in Superconducting Dirac and Weyl Semimetals. PHYSICAL REVIEW LETTERS 2020; 124:257001. [PMID: 32639774 DOI: 10.1103/physrevlett.124.257001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
Time-reversal invariant Dirac and Weyl semimetals in three dimensions (3D) can host open Fermi arcs and spin-momentum locking Fermi loops on the surfaces. We find that when they become superconducting with s-wave pairing and the doping is lower than a critical level, straight π-flux vortex lines terminating at surfaces with Fermi arcs or spin-momentum locking Fermi loops can realize 1D topological superconductivity and harbor Majorana zero modes at their ends. Remarkably, we find that the vortex-generation-associated Zeeman field can open (when the surfaces have only Fermi arcs) or enhance the topological gap protecting Majorana zero modes, which is contrary to the situation in superconducting topological insulators. By studying the tilting effect of bulk Dirac and Weyl cones, we further find that type-I Dirac and Weyl semimetals in general have a much broader topological regime than type-II ones. Our findings build up a connection between time-reversal invariant Dirac and Weyl semimetals and Majorana zero modes in vortices.
Collapse
Affiliation(s)
- Zhongbo Yan
- School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhigang Wu
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
| | - Wen Huang
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
| |
Collapse
|
29
|
Kononov A, Abulizi G, Qu K, Yan J, Mandrus D, Watanabe K, Taniguchi T, Schönenberger C. One-Dimensional Edge Transport in Few-Layer WTe 2. NANO LETTERS 2020; 20:4228-4233. [PMID: 32396010 PMCID: PMC7291355 DOI: 10.1021/acs.nanolett.0c00658] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/19/2020] [Indexed: 05/05/2023]
Abstract
WTe2 is a layered transitional-metal dichalcogenide (TMD) with a number of intriguing topological properties. Recently, WTe2 has been predicted to be a higher-order topological insulator (HOTI) with topologically protected hinge states along the edges. The gapless nature of WTe2 complicates the observation of one-dimensional (1D) topological states in transport due to their small contribution relative to the bulk. Here, we study the behavior of the Josephson effect in magnetic field to distinguish edge from bulk transport. The Josephson effect in few-layer WTe2 reveals 1D states residing on the edges and steps. Moreover, our data demonstrates a combination of Josephson transport properties observed solely in another HOTI-bismuth, including Josephson transport over micrometer distances, extreme robustness in a magnetic field, and nonsinusoidal current-phase relation (CPR). Our observations strongly suggest the topological origin of the 1D states and that few-layer WTe2 is a HOTI.
Collapse
Affiliation(s)
- Artem Kononov
- Department
of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
- Institute
of Solid State Physics of the Russian Academy of Sciences - Chernogolovka, Moscow District, Academician Ossipyan
str. 2, Chernogolovka 142432, Russia
| | - Gulibusitan Abulizi
- Department
of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Kejian Qu
- Department
of Materials Science and Engineering, University
of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jiaqiang Yan
- Department
of Materials Science and Engineering, University
of Tennessee, Knoxville, Tennessee 37996, United States
- Materials
Science and Technology Division, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - David Mandrus
- Department
of Materials Science and Engineering, University
of Tennessee, Knoxville, Tennessee 37996, United States
- Materials
Science and Technology Division, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Kenji Watanabe
- National
Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- National
Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Christian Schönenberger
- Department
of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
- Swiss Nanoscience
Institute, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| |
Collapse
|
30
|
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
|
31
|
Xing Y, Shao Z, Ge J, Luo J, Wang J, Zhu Z, Liu J, Wang Y, Zhao Z, Yan J, Mandrus D, Yan B, Liu XJ, Pan M, Wang J. Surface superconductivity in the type II Weyl semimetal TaIrTe 4. Natl Sci Rev 2020; 7:579-587. [PMID: 34692077 PMCID: PMC8288950 DOI: 10.1093/nsr/nwz204] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 11/13/2022] Open
Abstract
The search for unconventional superconductivity in Weyl semimetal materials is currently an exciting pursuit, since such superconducting phases could potentially be topologically non-trivial and host exotic Majorana modes. The layered material TaIrTe4 is a newly predicted time-reversal invariant type II Weyl semimetal with the minimum number of Weyl points. Here, we report the discovery of surface superconductivity in Weyl semimetal TaIrTe4. Our scanning tunneling microscopy/spectroscopy (STM/STS) visualizes Fermi arc surface states of TaIrTe4 that are consistent with the previous angle-resolved photoemission spectroscopy results. By a systematic study based on STS at ultralow temperature, we observe uniform superconducting gaps on the sample surface. The superconductivity is further confirmed by electrical transport measurements at ultralow temperature, with an onset transition temperature (T c) up to 1.54 K being observed. The normalized upper critical field h*(T/T c) behavior and the stability of the superconductivity against the ferromagnet indicate that the discovered superconductivity is unconventional with the p-wave pairing. The systematic STS, and thickness- and angular-dependent transport measurements reveal that the detected superconductivity is quasi-1D and occurs in the surface states. The discovery of the surface superconductivity in TaIrTe4 provides a new novel platform to explore topological superconductivity and Majorana modes.
Collapse
Affiliation(s)
- Ying Xing
- Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum, Beijing 102249, China
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Zhibin Shao
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an 710119, China
| | - Jun Ge
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Jiawei Luo
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Jinhua Wang
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zengwei Zhu
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jun Liu
- Center of Electron Microscopy, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yong Wang
- Center of Electron Microscopy, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhiying Zhao
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA
| | - Jiaqiang Yan
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - David Mandrus
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Xiong-Jun Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Minghu Pan
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an 710119, China
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| |
Collapse
|
32
|
Magnetoelastoresistance in WTe 2: Exploring electronic structure and extremely large magnetoresistance under strain. Proc Natl Acad Sci U S A 2019; 116:25524-25529. [PMID: 31792191 DOI: 10.1073/pnas.1910695116] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Strain describes the deformation of a material as a result of applied stress. It has been widely employed to probe transport properties of materials, ranging from semiconductors to correlated materials. In order to understand, and eventually control, transport behavior under strain, it is important to quantify the effects of strain on the electronic bandstructure, carrier density, and mobility. Here, we demonstrate that much information can be obtained by exploring magnetoelastoresistance (MER), which refers to magnetic field-driven changes of the elastoresistance. We use this powerful approach to study the combined effect of strain and magnetic fields on the semimetallic transition metal dichalcogenide [Formula: see text] We discover that WTe2 shows a large and temperature-nonmonotonic elastoresistance, driven by uniaxial stress, that can be tuned by magnetic field. Using first-principle and analytical low-energy model calculations, we provide a semiquantitative understanding of our experimental observations. We show that in [Formula: see text], the strain-induced change of the carrier density dominates the observed elastoresistance. In addition, the change of the mobilities can be directly accessed by using MER. Our analysis also reveals the importance of a heavy-hole band near the Fermi level on the elastoresistance at intermediate temperatures. Systematic understanding of strain effects in single crystals of correlated materials is important for future applications, such as strain tuning of bulk phases and fabrication of devices controlled by strain.
Collapse
|
33
|
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: 38] [Impact Index Per Article: 7.6] [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
|
34
|
Zhu YL, Hu J, Womack FN, Graf D, Wang Y, Adams PW, Mao ZQ. Emergence of intrinsic superconductivity below 1.178 K in the topologically non-trivial semimetal state of CaSn 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:245703. [PMID: 30861508 DOI: 10.1088/1361-648x/ab0f0d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Topological materials which are also superconducting are of great current interest, since they may exhibit a non-trivial topologically-mediated superconducting phase. Although there have been many reports of pressure-tuned or chemical-doping-induced superconductivity in a variety of topological materials, there have been few examples of intrinsic, ambient pressure superconductivity in a topological system having a stoichiometric composition. Here, we report that the pure intermetallic CaSn3 not only exhibits topological fermion properties, but also has a superconducting phase at ~1.178 K under ambient pressure. The topological fermion properties, including the nearly zero quasi-particle mass and the non-trivial Berry phase accumulated in cyclotron motions, were revealed from the de Haas-van Alphen (dHvA) quantum oscillation studies of this material. Although CaSn3 was previously reported to be superconducting with T c = 4.2 K, our studies show that the T c = 4.2 K superconductivity is extrinsic and caused by Sn on the degraded surface, whereas its intrinsic bulk superconducting transition occurs at 1.178 K. These findings make CaSn3 a promising candidate for exploring new exotic states arising from the interplay between non-trivial band topology and superconductivity, e.g. topological superconductivity (TSC).
Collapse
Affiliation(s)
- Y L Zhu
- Physics and Engineering Physics department, Tulane University, New Orleans, LA 70118, United States of America
| | | | | | | | | | | | | |
Collapse
|
35
|
Wang Y, Wang L, Liu X, Wu H, Wang P, Yan D, Cheng B, Shi Y, Watanabe K, Taniguchi T, Liang SJ, Miao F. Direct Evidence for Charge Compensation-Induced Large Magnetoresistance in Thin WTe 2. NANO LETTERS 2019; 19:3969-3975. [PMID: 31082263 DOI: 10.1021/acs.nanolett.9b01275] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Since the discovery of extremely large nonsaturating magnetoresistance (MR) in WTe2, much effort has been devoted to understanding the underlying mechanism, which is still under debate. Here, we explicitly identify the dominant physical origin of the large nonsaturating MR through in situ tuning of the magneto-transport properties in thin WTe2 film. With an electrostatic doping approach, we observed a nonmonotonic gate dependence of the MR. The MR reaches a maximum (10600%) in thin WTe2 film at certain gate voltage where electron and hole concentrations are balanced, indicating that the charge compensation is the dominant mechanism of the observed large MR. Besides, we show that the temperature-dependent magnetoresistance exhibits similar tendency with the carrier mobility when the charge compensation is retained, revealing that distinct scattering mechanisms may be at play for the temperature dependence of magneto-transport properties. Our work would be helpful for understanding mechanism of the large MR in other nonmagnetic materials and offers an avenue for achieving large MR in the nonmagnetic materials with electron-hole pockets.
Collapse
Affiliation(s)
- Yaojia Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Lizheng Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Xiaowei Liu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Heng Wu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Pengfei Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Dayu Yan
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Bin Cheng
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Youguo Shi
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Kenji Watanabe
- National Institute for Materials Science , 1-1 Namiki Tsukuba , Ibaraki 305-0044 , Japan
| | - Takashi Taniguchi
- National Institute for Materials Science , 1-1 Namiki Tsukuba , Ibaraki 305-0044 , Japan
| | - Shi-Jun Liang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Feng Miao
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| |
Collapse
|
36
|
Ma H, Wan Z, Li J, Wu R, Zhang Z, Li B, Zhao B, Qian Q, Liu Y, Xia Q, Guo G, Duan X, Duan X. Phase-Tunable Synthesis of Ultrathin Layered Tetragonal CoSe and Nonlayered Hexagonal CoSe Nanoplates. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1900901. [PMID: 31045286 DOI: 10.1002/adma.201900901] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/15/2019] [Indexed: 06/09/2023]
Abstract
Multiple structural phases in transition metal dichalcogenides have attracted considerable recent interest for their tunable chemical and electronic properties. Herein, a chemical vapor deposition route to ultrathin CoSe nanoplates with tunable structure phases is reported. By precisely tailoring the growth temperature, ultrathin 2D layered tetragonal CoSe nanoplates and nonlayered hexagonal CoSe nanoplates can be selectively prepared as square or hexagonal geometries, with thickness as thin as 2.3 and 3.7 nm, respectively. X-ray diffraction, transmission electron microscopy, and selected area electron diffraction studies show that both types of nanoplates are high-quality single crystals. Electrical transport studies reveal that both the tetragonal and hexagonal CoSe nanoplates show strong thickness-tunable electrical properties and excellent breakdown current density. The 2D hexagonal CoSe nanoplates display metallic behavior with an excellent conductivity up to 6.6 × 105 S m-1 and an extraordinary breakdown current density up to 3.9 × 107 A cm-2 , while the square tetragonal nanoplates show considerably lower conductivity up to 8.2 × 104 S m-1 with angle-dependent magnetoresistance and weak antilocalization effect at lower field. This study offers a tunable material system for exploring multiphase 2D materials and their potential applications for electronic and magnetoelectronic devices.
Collapse
Affiliation(s)
- Huifang Ma
- Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Zhong Wan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Jia Li
- Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Ruixia Wu
- Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Zhengwei Zhang
- Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Bo Li
- Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Bei Zhao
- Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Qi Qian
- Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Yuan Liu
- Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Qinglin Xia
- School of Physics and Electronics, Central South University, Changsha, 410083, China
| | - Guanghua Guo
- School of Physics and Electronics, Central South University, Changsha, 410083, China
| | - Xidong Duan
- Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Xiangfeng Duan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| |
Collapse
|
37
|
Wang Q, Yesilyurt C, Liu F, Siu ZB, Cai K, Kumar D, Liu Z, Jalil MBA, Yang H. Anomalous Photothermoelectric Transport Due to Anisotropic Energy Dispersion in WTe 2. NANO LETTERS 2019; 19:2647-2652. [PMID: 30859825 DOI: 10.1021/acs.nanolett.9b00513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Band structures are vital in determining the electronic properties of materials. Recently, the two-dimensional (2D) semimetallic transition metal tellurides (WTe2 and MoTe2) have sparked broad research interest because of their elliptical or open Fermi surface, making distinct from the conventional 2D materials. In this study, we demonstrate a centrosymmetric photothermoelectric voltage distribution in WTe2 nanoflakes, which has not been observed in common 2D materials such as graphene and MoS2. Our theoretical model shows the anomalous photothermoelectric effect arises from an anisotropic energy dispersion and micrometer-scale hot carrier diffusion length of WTe2. Further, our results are more consistent with the anisotropic tilt direction of energy dispersion being aligned to the b-axis rather than the a-axis of the WTe2 crystal, which is consistent with the previous first-principle calculations as well as magneto-transport experiments. Our work shows the photothermoelectric current is strongly confined to the anisotropic direction of the energy dispersion in WTe2, which opens an avenue for interesting electro-optic applications such as electron beam collimation and electron lenses.
Collapse
Affiliation(s)
- Qisheng Wang
- Department of Electrical and Computer Engineering , National University of Singapore , 117576 , Singapore
| | - Can Yesilyurt
- Department of Electrical and Computer Engineering , National University of Singapore , 117576 , Singapore
| | - Fucai Liu
- Center for Programmable Materials, School of Electrical and Electronic Engineering , Nanyang Technology University , 639798 , Singapore
| | - Zhuo Bin Siu
- Department of Electrical and Computer Engineering , National University of Singapore , 117576 , Singapore
| | - Kaiming Cai
- Department of Electrical and Computer Engineering , National University of Singapore , 117576 , Singapore
| | - Dushyant Kumar
- Department of Electrical and Computer Engineering , National University of Singapore , 117576 , Singapore
| | - Zheng Liu
- Center for Programmable Materials, School of Electrical and Electronic Engineering , Nanyang Technology University , 639798 , Singapore
| | - Mansoor B A Jalil
- Department of Electrical and Computer Engineering , National University of Singapore , 117576 , Singapore
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering , National University of Singapore , 117576 , Singapore
| |
Collapse
|
38
|
Cucchi I, Gutiérrez-Lezama I, Cappelli E, McKeown Walker S, Bruno FY, Tenasini G, Wang L, Ubrig N, Barreteau C, Giannini E, Gibertini M, Tamai A, Morpurgo AF, Baumberger F. Microfocus Laser-Angle-Resolved Photoemission on Encapsulated Mono-, Bi-, and Few-Layer 1T'-WTe 2. NANO LETTERS 2019; 19:554-560. [PMID: 30570259 DOI: 10.1021/acs.nanolett.8b04534] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Two-dimensional crystals of semi-metallic van der Waals materials hold much potential for the realization of novel phases, as exemplified by the recent discoveries of a polar metal in few-layer 1T'-WTe2 and of a quantum spin Hall state in monolayers of the same material. Understanding these phases is particularly challenging because little is known from experiments about the momentum space electronic structure of ultrathin crystals. Here, we report direct electronic structure measurements of exfoliated mono-, bi-, and few-layer 1T'-WTe2 by laser-based microfocus angle-resolved photoemission. This is achieved by encapsulating with monolayer graphene a flake of WTe2 comprising regions of different thickness. Our data support the recent identification of a quantum spin Hall state in monolayer 1T'-WTe2 and reveal strong signatures of the broken inversion symmetry in the bilayer. We finally discuss the sensitivity of encapsulated samples to contaminants following exposure to ambient atmosphere.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Marco Gibertini
- National Centre for Computational Design and Discovery of Novel Materials (MARVEL) , École Polytechnique Fedérale de Lausanne , CH-1015 Lausanne , Switzerland
| | | | | | - Felix Baumberger
- Swiss Light Source , Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| |
Collapse
|
39
|
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]
|
40
|
Li Q, He C, Wang Y, Liu E, Wang M, Wang Y, Zeng J, Ma Z, Cao T, Yi C, Wang N, Watanabe K, Taniguchi T, Shao L, Shi Y, Chen X, Liang SJ, Wang QH, Miao F. Proximity-Induced Superconductivity with Subgap Anomaly in Type II Weyl Semi-Metal WTe 2. NANO LETTERS 2018; 18:7962-7968. [PMID: 30403355 DOI: 10.1021/acs.nanolett.8b03924] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Due to the nontrivial topological band structure in type II Weyl semi-metal tungsten ditelluride (WTe2), unconventional properties may emerge in its superconducting phase. While realizing intrinsic superconductivity has been challenging in the type II Weyl semi-metal WTe2, the proximity effect may open an avenue for the realization of superconductivity. Here, we report the observation of proximity-induced superconductivity with a long coherence length along the c axis in WTe2 thin flakes based on a WTe2/NbSe2 van der Waals heterostructure. Interestingly, we also observe anomalous oscillations of the differential resistance during the transition from the superconducting to the normal state. Theoretical calculations show excellent agreement with experimental results, revealing that such a subgap anomaly is the intrinsic property of WTe2 in superconducting state induced by the proximity effect. Our findings enrich the understanding of the superconducting phase of type II Weyl semi-metals and pave the way for their future applications in topological quantum computing.
Collapse
Affiliation(s)
- Qiao Li
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Chaocheng He
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Yaojia Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Erfu Liu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Miao Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Yu Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Junwen Zeng
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Zecheng Ma
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Tianjun Cao
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Changjiang Yi
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | | | - Kenji Watanabe
- National Institute for Materials Science , 1-1 Namiki Tsukuba , Ibaraki 305-0044 , Japan
| | - Takashi Taniguchi
- National Institute for Materials Science , 1-1 Namiki Tsukuba , Ibaraki 305-0044 , Japan
| | - Lubing Shao
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Youguo Shi
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | | | - Shi-Jun Liang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Qiang-Hua Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Feng Miao
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| |
Collapse
|
41
|
Hoang AT, Shinde SM, Katiyar AK, Dhakal KP, Chen X, Kim H, Lee SW, Lee Z, Ahn JH. Orientation-dependent optical characterization of atomically thin transition metal ditellurides. NANOSCALE 2018; 10:21978-21984. [PMID: 30451270 DOI: 10.1039/c8nr07592a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Molybdenum ditellurides (MoTe2) have recently attracted attention owing to their excellent structurally tunable nature between 1T'(metallic)- and 2H(semiconducting)-phases; thus, the controllable fabrication and critical identification of MoTe2 are highly desired. Here, we semi-controllably synthesized 1T'- and 2H-MoTe2 crystals using the atmospheric pressure chemical vapor deposition (APCVD) technique and studied their grain-orientation dependency using polarization-sensitive optical microscopy, Raman scattering, and second-harmonic generation (SHG) microspectroscopy. The polycrystalline 1T'-MoTe2 phase with quasi-1D "Mo-Mo" zigzag chains showed anisotropic optical absorption, leading to a clear visualization of the lattice domains. On the other hand, 2H-MoTe2 lattice grains did not exhibit any discernible difference under polarized light illumination. The combined aforementioned microscopy techniques could be used as an easy-to-access and non-destructive tool for a quick and solid identification of intended lattice orientation development in industry-scale MoTe2 crystal manufacturing.
Collapse
Affiliation(s)
- Anh Tuan Hoang
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Fatemi V, Wu S, Cao Y, Bretheau L, Gibson QD, Watanabe K, Taniguchi T, Cava RJ, Jarillo-Herrero P. Electrically tunable low-density superconductivity in a monolayer topological insulator. Science 2018; 362:926-929. [DOI: 10.1126/science.aar4642] [Citation(s) in RCA: 204] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 10/09/2018] [Indexed: 01/14/2023]
Affiliation(s)
- Valla Fatemi
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sanfeng Wu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yuan Cao
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Landry Bretheau
- Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA, 91128 Palaiseau Cedex, France
| | - Quinn D. Gibson
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZX, UK
| | - Kenji Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Robert J. Cava
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Pablo Jarillo-Herrero
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
43
|
Sajadi E, Palomaki T, Fei Z, Zhao W, Bement P, Olsen C, Luescher S, Xu X, Folk JA, Cobden DH. Gate-induced superconductivity in a monolayer topological insulator. Science 2018; 362:922-925. [PMID: 30361385 DOI: 10.1126/science.aar4426] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 10/05/2018] [Indexed: 01/14/2023]
Abstract
The layered semimetal tungsten ditelluride (WTe2) has recently been found to be a two-dimensional topological insulator (2D TI) when thinned down to a single monolayer, with conducting helical edge channels. We found that intrinsic superconductivity can be induced in this monolayer 2D TI by mild electrostatic doping at temperatures below 1 kelvin. The 2D TI-superconductor transition can be driven by applying a small gate voltage. This discovery offers possibilities for gate-controlled devices combining superconductivity and nontrivial topological properties, and could provide a basis for quantum information schemes based on topological protection.
Collapse
Affiliation(s)
- Ebrahim Sajadi
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada, and Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Tauno Palomaki
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | - Zaiyao Fei
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | - Wenjin Zhao
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | - Philip Bement
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada, and Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Christian Olsen
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada, and Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Silvia Luescher
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada, and Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA 98195, USA.,Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, USA
| | - Joshua A Folk
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada, and Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
| | - David H Cobden
- Department of Physics, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|
44
|
Zhu L, Li QY, Lv YY, Li S, Zhu XY, Jia ZY, Chen YB, Wen J, Li SC. Superconductivity in Potassium-Intercalated T d-WTe 2. NANO LETTERS 2018; 18:6585-6590. [PMID: 30226053 DOI: 10.1021/acs.nanolett.8b03180] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
To realize a topological superconductor is one of the most attracting topics because of its great potential in quantum computation. In this study, we successfully intercalate potassium (K) into the van der Waals gap of type II Weyl semimetal WTe2 and discover the superconducting state in K xWTe2 through both electrical transport and scanning tunneling spectroscopy measurements. The superconductivity exhibits an evident anisotropic behavior. Moreover, we also uncover the coexistence of superconductivity and the positive magnetoresistance state. Structural analysis substantiates the negligible lattice expansion induced by the intercalation, therefore suggesting K-intercalated WTe2 still hosts the topological nontrivial state. These results indicate that the K-intercalated WTe2 may be a promising candidate to explore the topological superconductor.
Collapse
Affiliation(s)
- Li Zhu
- National Laboratory of Solid State Microstructures, School of Physics , Nanjing University , Nanjing 210093 , China
| | - Qi-Yuan Li
- National Laboratory of Solid State Microstructures, School of Physics , Nanjing University , Nanjing 210093 , China
| | - Yang-Yang Lv
- National Laboratory of Solid State Microstructures, Department of Materials Science and Engineering , Nanjing University , Nanjing 210093 , China
| | - Shichao Li
- National Laboratory of Solid State Microstructures, School of Physics , Nanjing University , Nanjing 210093 , China
| | - Xin-Yang Zhu
- National Laboratory of Solid State Microstructures, School of Physics , Nanjing University , Nanjing 210093 , China
| | - Zhen-Yu Jia
- National Laboratory of Solid State Microstructures, School of Physics , Nanjing University , Nanjing 210093 , China
| | - Y B Chen
- National Laboratory of Solid State Microstructures, School of Physics , Nanjing University , Nanjing 210093 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Jinsheng Wen
- National Laboratory of Solid State Microstructures, School of Physics , Nanjing University , Nanjing 210093 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| | - Shao-Chun Li
- National Laboratory of Solid State Microstructures, School of Physics , Nanjing University , Nanjing 210093 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China
| |
Collapse
|
45
|
Li X, Sun J, Shahi P, Gao M, MacDonald AH, Uwatoko Y, Xiang T, Goodenough JB, Cheng J, Zhou J. Pressure-induced phase transitions and superconductivity in a black phosphorus single crystal. Proc Natl Acad Sci U S A 2018; 115:9935-9940. [PMID: 30217890 PMCID: PMC6176577 DOI: 10.1073/pnas.1810726115] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We report a thorough study of the transport properties of the normal and superconducting states of black phosphorus (BP) under magnetic field and high pressure with a large-volume apparatus that provides hydrostatic pressure to induce transitions from the layered A17 phase to the layered A7 phase and to the cubic phase of BP. Quantum oscillations can be observed at P ≥ 1 GPa in both resistivity and Hall voltage, and their evolutions with pressure in the A17 phase imply a continuous enlargement of Fermi surface. A significantly large magnetoresistance (MR) at low temperatures is observed in the A7 phase that becomes superconducting below a superconducting transition temperature Tc ∼ 6-13 K. Tc increases continuously with pressure on crossing the A7 to the cubic phase boundary. The strong MR effect can be fit by a modified Kohler's rule. A correlation between Tc and fitting parameters suggests that phonon-mediated interactions play dominant roles in driving the Cooper pairing, which is further supported by our density functional theory (DFT) calculations. The change of effective carrier mobility in the A17 phase under pressure derived from the MR effect is consistent with that obtained from the temperature dependence of the quantum oscillations. In situ single-crystal diffraction under high pressure indicates a total structural reconstruction instead of simple stretching of the A17 phase layers in the A17-to-A7-phase transition. This finding helps us to interpret transport properties on crossing the phase transition under high pressure.
Collapse
Affiliation(s)
- Xiang Li
- Materials Science and Engineering Program, The University of Texas at Austin, Austin, TX 78712
| | - Jianping Sun
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Prashant Shahi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
- Department of Physics, Deen Dayal Upadhyaya Gorakhpur University, Gorakhpur 273009, India
| | - Miao Gao
- Department of Microelectronics Science and Engineering, Faculty of Sciences, Ningbo University, Zhejiang 315211, China
| | - Allan H MacDonald
- Department of Physics, The University of Texas at Austin, Austin, TX 78712
| | - Yoshiya Uwatoko
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Tao Xiang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Centre of Quantum Matter, Beijing 100871, China
| | - John B Goodenough
- Materials Science and Engineering Program, The University of Texas at Austin, Austin, TX 78712;
| | - Jinguang Cheng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianshi Zhou
- Materials Science and Engineering Program, The University of Texas at Austin, Austin, TX 78712;
| |
Collapse
|
46
|
Origin of extremely large magnetoresistance in the candidate type-II Weyl semimetal MoTe 2-x. Sci Rep 2018; 8:13937. [PMID: 30224789 PMCID: PMC6141610 DOI: 10.1038/s41598-018-32387-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/05/2018] [Indexed: 11/21/2022] Open
Abstract
The recent observation of extremely large magnetoresistance (MR) in the transition-metal dichalcogenide MoTe2 has attracted considerable interest due to its potential technological applications as well as its relationship with novel electronic states predicted for a candidate type-II Weyl semimetal. In order to understand the origin of the MR, the electronic structure of MoTe2−x (x = 0.08) is systematically tuned by application of pressure and probed via its Hall and longitudinal conductivities. With increasing pressure, a monoclinic-to-orthorhombic (1 T′ to Td) structural phase transition temperature (T*) gradually decreases from 210 K at 1 bar to 58 K at 1.1 GPa, and there is no anomaly associated with the phase transition at 1.4 GPa, indicating that a T = 0 K quantum phase transition occurs at a critical pressure (Pc) between 1.1 and 1.4 GPa. The large MR observed at 1 bar is suppressed with increasing pressure and is almost saturated at 100% for P > Pc. The dependence on magnetic field of the Hall and longitudinal conductivities of MoTe2−x shows that a pair of electron and hole bands are important in the low-pressure Td phase, while another pair of electron and hole bands are additionally required in the high-pressure 1 T′ phase. The MR peaks at a characteristic hole-to-electron concentration ratio (nc) and is sharply suppressed when the ratio deviates from nc within the Td phase. These results establish the comprehensive temperature-pressure phase diagram of MoTe2−x and underscore that its MR originates from balanced electron-hole carrier concentrations.
Collapse
|
47
|
Huang C, Narayan A, Zhang E, Liu Y, Yan X, Wang J, Zhang C, Wang W, Zhou T, Yi C, Liu S, Ling J, Zhang H, Liu R, Sankar R, Chou F, Wang Y, Shi Y, Law KT, Sanvito S, Zhou P, Han Z, Xiu F. Inducing Strong Superconductivity in WTe 2 by a Proximity Effect. ACS NANO 2018; 12:7185-7196. [PMID: 29901987 DOI: 10.1021/acsnano.8b03102] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The search for proximity-induced superconductivity in topological materials has generated widespread interest in the condensed matter physics community. The superconducting states inheriting nontrivial topology at interfaces are expected to exhibit exotic phenomena such as topological superconductivity and Majorana zero modes, which hold promise for applications in quantum computation. However, a practical realization of such hybrid structures based on topological semimetals and superconductors has hitherto been limited. Here, we report the strong proximity-induced superconductivity in type-II Weyl semimetal WTe2, in a van der Waals hybrid structure obtained by mechanically transferring NbSe2 onto various thicknesses of WTe2. When the WTe2 thickness ( tWTe2) reaches 21 nm, the superconducting transition occurs around the critical temperature ( Tc) of NbSe2 with a gap amplitude (Δp) of 0.38 meV and an unexpected ultralong proximity length ( lp) up to 7 μm. With the thicker 42 nm WTe2 layer, however, the proximity effect yields Tc ≈ 1.2 K, Δp = 0.07 meV, and a short lp of less than 1 μm. Our theoretical calculations, based on the Bogoliubov-de Gennes equations in the clean limit, predict that the induced superconducting gap is a sizable fraction of the NbSe2 superconducting one when tWTe2 is less than 30 nm and then decreases quickly as tWTe2 increases. This agrees qualitatively well with the experiments. Such observations form a basis in the search for superconducting phases in topological semimetals.
Collapse
Affiliation(s)
- Ce Huang
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Awadhesh Narayan
- Materials Theory , ETH Zurich , Wolfgang-Pauli-Strasse 27 , CH 8093 Zurich , Switzerland
| | - Enze Zhang
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Yanwen Liu
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Xiao Yan
- State Key Laboratory of ASIC and System, Department of Microelectronics , Fudan University , Shanghai 200433 , China
| | - Jiaxiang Wang
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Cheng Zhang
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Weiyi Wang
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Tong Zhou
- Department of Physics , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong, China
| | - Changjiang Yi
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Shanshan Liu
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Jiwei Ling
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Huiqin Zhang
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Ran Liu
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China
- Institute for Nanoelectronic Devices and Quantum Computing , Fudan University , Shanghai 200433 , China
| | - Raman Sankar
- Institute of Physics , Academia Sinica , Taipei 11529 , Taiwan, China
- Center for Condensed Matter Sciences , National Taiwan University , Taipei 10617 , Taiwan, China
| | - Fangcheng Chou
- Center for Condensed Matter Sciences , National Taiwan University , Taipei 10617 , Taiwan, China
- National Synchrotron Radiation Research Center , Hsinchu 30076 , Taiwan, China
- Taiwan Consortium of Emergent Crystalline Materials , Ministry of Science and Technology , Taipei 10622 , Taiwan, China
| | - Yihua Wang
- School of Physical Sciences , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Youguo Shi
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics , Chinese Academy of Sciences , Beijing 100190 , China
- School of Physical Sciences , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Kam Tuen Law
- Department of Physics , The Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong, China
| | - Stefano Sanvito
- School of Physics, AMBER and CRANN Institute , Trinity College , Dublin 2 , Ireland
| | - Peng Zhou
- State Key Laboratory of ASIC and System, Department of Microelectronics , Fudan University , Shanghai 200433 , China
| | - Zheng Han
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110016 , China
| | - Faxian Xiu
- School of Physical Sciences , University of Chinese Academy of Sciences , Beijing 100190 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| |
Collapse
|
48
|
Ying J, Paudyal H, Heil C, Chen XJ, Struzhkin VV, Margine ER. Unusual Pressure-Induced Periodic Lattice Distortion in SnSe_{2}. PHYSICAL REVIEW LETTERS 2018; 121:027003. [PMID: 30085758 DOI: 10.1103/physrevlett.121.027003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Indexed: 06/08/2023]
Abstract
We performed high-pressure x-ray diffraction (XRD), Raman, and transport measurements combined with first-principles calculations to investigate the behavior of tin diselenide (SnSe_{2}) under compression. The obtained single-crystal XRD data indicate the formation of a (1/3,1/3,0)-type superlattice above 17 GPa. According to our density functional theory results, the pressure-induced transition to the commensurate periodic lattice distortion (PLD) phase is due to the combined effect of strong Fermi surface nesting and electron-phonon coupling at a momentum wave vector q=(1/3,1/3,0). In contrast, similar PLD transitions associated with charge density wave (CDW) orderings in transition metal dichalcogenides (TMDs) do not involve significant Fermi surface nesting. The discovered pressure-induced PLD is quite remarkable, as pressure usually suppresses CDW phases in related materials. Our findings, therefore, provide new playgrounds to study the intricate mechanisms governing the emergence of PLD in TMD-related materials.
Collapse
Affiliation(s)
- Jianjun Ying
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
- HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA
| | - Hari Paudyal
- Department of Physics, Applied Physics, and Astronomy, Binghamton University-SUNY, Binghamton, New York 13902, USA
| | - Christoph Heil
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
- Institute of Theoretical and Computational Physics, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
| | - Xiao-Jia Chen
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Viktor V Struzhkin
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
| | - Elena R Margine
- Department of Physics, Applied Physics, and Astronomy, Binghamton University-SUNY, Binghamton, New York 13902, USA
| |
Collapse
|
49
|
Tian W, Yu W, Liu X, Wang Y, Shi J. A Review of the Characteristics, Synthesis, and Thermodynamics of Type-II Weyl Semimetal WTe₂. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E1185. [PMID: 29996559 PMCID: PMC6073882 DOI: 10.3390/ma11071185] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/06/2018] [Accepted: 07/06/2018] [Indexed: 12/12/2022]
Abstract
WTe₂ as a candidate of transition metal dichalcogenides (TMDs) exhibits many excellent properties, such as non-saturable large magnetoresistance (MR). Firstly, the crystal structure and characteristics of WTe₂ are introduced, followed by a summary of the synthesis methods. Its thermodynamic properties are highlighted due to the insufficient research. Finally, a comprehensive analysis and discussion are introduced to interpret the advantages, challenges, and future prospects. Some results are shown as follows. (1) The chiral anomaly, pressure-induced conductivity, and non-saturable large MR are all unique properties of WTe₂ that attract wide attention, but it is also a promising thermoelectric material that holds anisotropic ultra-low thermal conductivity (0.46 W·m−1·K−1). WTe₂ is expected to have the lowest thermal conductivity, owing to the heavy atom mass and low Debye temperature. (2) The synthesis methods influence the properties significantly. Although large-scale few-layer WTe₂ in high quality can be obtained by many methods, the preparation has not yet been industrialized, which limits its applications. (3) The thermodynamic properties of WTe₂ are influenced by temperature, scale, and lattice orientations. However, the in-plane anisotropy cannot be observed in the experiment, as the intrinsic property is suppressed by defects and boundary scattering. Overall, this work provides an opportunity to develop the applications of WTe₂.
Collapse
Affiliation(s)
- Wenchao Tian
- School of Electro-Mechanical Engineering, Xidian University, Number 2 Taibai South Road, Xi'an 710071, China.
| | - Wenbo Yu
- School of Electro-Mechanical Engineering, Xidian University, Number 2 Taibai South Road, Xi'an 710071, China.
| | - Xiaohan Liu
- School of Electro-Mechanical Engineering, Xidian University, Number 2 Taibai South Road, Xi'an 710071, China.
| | - Yongkun Wang
- School of Electro-Mechanical Engineering, Xidian University, Number 2 Taibai South Road, Xi'an 710071, China.
| | - Jing Shi
- School of Electro-Mechanical Engineering, Xidian University, Number 2 Taibai South Road, Xi'an 710071, China.
| |
Collapse
|
50
|
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: 109] [Impact Index Per Article: 18.2] [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
|