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Rosenstein B, Shapiro BY. Two step I to II type transitions in layered Weyl semi-metals and their impact on superconductivity. Sci Rep 2023; 13:8450. [PMID: 37231114 DOI: 10.1038/s41598-023-35704-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/22/2023] [Indexed: 05/27/2023] Open
Abstract
Novel "quasi two dimensional" typically layered (semi) metals offer a unique opportunity to control the density and even the topology of the electronic matter. Along with doping and gate voltage, a robust tuning is achieved by application of the hydrostatic pressure. In Weyl semi-metals the tilt of the dispersion relation cones, [Formula: see text] increases with pressure, so that one is able to reach type II ([Formula: see text]starting from the more conventional type I Weyl semi-metals [Formula: see text]. The microscopic theory of such a transition is constructed. It is found that upon increasing pressure the I to II transition occurs in two continuous steps. In the first step the cones of opposite chirality coalesce so that the chiral symmetry is restored, while the second transition to the Fermi surface extending throughout the Brillouin zone occurs at higher pressures. Flattening of the band leads to profound changes in Coulomb screening. Superconductivity observed recently in wide range of pressure and chemical composition in Weyl semi-metals of both types. The phonon theory of pairing including the Coulomb repulsion for a layered material is constructed and applied to recent extensive experiments on [Formula: see text].
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Affiliation(s)
- Baruch Rosenstein
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, R.O.C
- Department of Physics, Institute of Superconductivity, Bar-Ilan University, 52900, Ramat Gan, Israel
| | - B Ya Shapiro
- Department of Physics, Institute of Superconductivity, Bar-Ilan University, 52900, Ramat Gan, Israel.
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Li Q, Zhang J, Zheng Q, Guo W, Cao J, Jin M, Zhang X, Li N, Wu Y, Ye X, Chen P, Zhu J, Wang T, Shi W, Wang F, Yang W, Qin X. Pressure-Induced Superconductivity in HgTe Single-Crystal Film. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2200590. [PMID: 35470581 PMCID: PMC9218769 DOI: 10.1002/advs.202200590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Indexed: 06/14/2023]
Abstract
HgTe film is widely used for quantum Hall well studies and devices, as it has unique properties, like band gap inversion, carrier-type switch, and topological evolution depending on the film thickness modulation near the so-called critical thickness (63.5 Å), while its counterpart bulk materials do not hold these nontrivial properties at ambient pressure. Here, much richer transport properties emerging in bulk HgTe crystal through pressure-tuning are reported. Not only the above-mentioned abnormal properties can be realized in a 400 nm thick bulk HgTe single crystal, but superconductivity is also discovered in a series of high-pressure phases. Combining crystal structure, electrical transport, and Hall coefficient measurements, a p-n carrier type switching is observed in the first high-pressure cinnabar phase. Superconductivity emerges after the semiconductor-to-metal transition at 3.9 GPa and persists up to 54 GPa, crossing four high-pressure phases with an increased upper critical field. Density functional theory calculations confirm that a surface-dominated topologic band structure contributes these exotic properties under high pressure. This discovery presents broad and efficient tuning effects by pressure on the lattice structure and electronic modulations compared to the thickness-dependent critical properties in 2D and 3D topologic insulators and semimetals.
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Affiliation(s)
- Qiang Li
- Department of PhysicsShanghai Normal UniversityShanghai200234China
- Center for High Pressure Science and Technology Advanced Research (HPSTAR)Shanghai201203China
| | - Jian Zhang
- State Key Lab of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai200083China
| | - Qunfei Zheng
- Department of PhysicsShanghai Normal UniversityShanghai200234China
- Center for High Pressure Science and Technology Advanced Research (HPSTAR)Shanghai201203China
| | - Wenyu Guo
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Jiangming Cao
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Meiling Jin
- Center for High Pressure Science and Technology Advanced Research (HPSTAR)Shanghai201203China
| | - Xingyu Zhang
- Department of PhysicsSouthern University of Science and TechnologyShenzhen518055China
| | - Nana Li
- Center for High Pressure Science and Technology Advanced Research (HPSTAR)Shanghai201203China
| | - Yanhui Wu
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Xiang Ye
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Pingping Chen
- State Key Lab of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai200083China
| | - Jinlong Zhu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR)Shanghai201203China
- Department of PhysicsSouthern University of Science and TechnologyShenzhen518055China
| | - Tao Wang
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Wangzhou Shi
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Feifei Wang
- Department of PhysicsShanghai Normal UniversityShanghai200234China
| | - Wenge Yang
- Center for High Pressure Science and Technology Advanced Research (HPSTAR)Shanghai201203China
| | - Xiaomei Qin
- Department of PhysicsShanghai Normal UniversityShanghai200234China
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3
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Ok JM, Mohanta N, Zhang J, Yoon S, Okamoto S, Choi ES, Zhou H, Briggeman M, Irvin P, Lupini AR, Pai YY, Skoropata E, Sohn C, Li H, Miao H, Lawrie B, Choi WS, Eres G, Levy J, Lee HN. Correlated oxide Dirac semimetal in the extreme quantum limit. SCIENCE ADVANCES 2021; 7:eabf9631. [PMID: 34524855 PMCID: PMC8443170 DOI: 10.1126/sciadv.abf9631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 07/23/2021] [Indexed: 05/25/2023]
Abstract
Quantum materials (QMs) with strong correlation and nontrivial topology are indispensable to next-generation information and computing technologies. Exploitation of topological band structure is an ideal starting point to realize correlated topological QMs. Here, we report that strain-induced symmetry modification in correlated oxide SrNbO3 thin films creates an emerging topological band structure. Dirac electrons in strained SrNbO3 films reveal ultrahigh mobility (μmax ≈ 100,000 cm2/Vs), exceptionally small effective mass (m* ~ 0.04me), and nonzero Berry phase. Strained SrNbO3 films reach the extreme quantum limit, exhibiting a sign of fractional occupation of Landau levels and giant mass enhancement. Our results suggest that symmetry-modified SrNbO3 is a rare example of correlated oxide Dirac semimetals, in which strong correlation of Dirac electrons leads to the realization of a novel correlated topological QM.
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Affiliation(s)
- Jong Mok Ok
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | | | - Jie Zhang
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Sangmoon Yoon
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | | | - Eun Sang Choi
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Hua Zhou
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Megan Briggeman
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA 15260, USA
| | - Patrick Irvin
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA 15260, USA
| | | | - Yun-Yi Pai
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | | | - Changhee Sohn
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Haoxiang Li
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Hu Miao
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | | | - Woo Seok Choi
- Department of Physics, Sungkyunkwan University, Suwon 16419, Korea
| | - Gyula Eres
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Jeremy Levy
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA 15260, USA
| | - Ho Nyung Lee
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Wang H, Liu Y, Liu Y, Xi C, Wang J, Liu J, Wang Y, Li L, Lau SP, Tian M, Yan J, Mandrus D, Dai JY, Liu H, Xie X, Wang J. Log-periodic quantum magneto-oscillations and discrete-scale invariance in topological material HfTe 5. Natl Sci Rev 2019; 6:914-920. [PMID: 34691952 PMCID: PMC8291527 DOI: 10.1093/nsr/nwz110] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/28/2019] [Accepted: 07/28/2019] [Indexed: 11/14/2022] Open
Abstract
Discrete-scale invariance (DSI) is a phenomenon featuring intriguing log-periodicity that can be rarely observed in quantum systems. Here, we report the log-periodic quantum oscillations in the longitudinal magnetoresistivity (ρxx ) and the Hall traces (ρyx ) of HfTe5 crystals, which reveal the DSI in the transport-coefficients matrix. The oscillations in ρxx and ρyx show the consistent logB-periodicity with a phase shift. The finding of the logB oscillations in the Hall resistance supports the physical mechanism as a general quantum effect originating from the resonant scattering. Combined with theoretical simulations, we further clarify the origin of the log-periodic oscillations and the DSI in the topological materials. This work evidences the universality of the DSI in the Dirac materials and provides indispensable information for a full understanding of this novel phenomenon.
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Affiliation(s)
- Huichao Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China
| | - Yanzhao Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Yongjie Liu
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Chuanying Xi
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Junfeng Wang
- 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
| | - Liang Li
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shu Ping Lau
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China
| | - Mingliang Tian
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Jiaqiang Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - David Mandrus
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Ji-Yan Dai
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Xincheng Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, 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
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, 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
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Abstract
The temperature dependence of the resistivity (ρ) of Ag-doped Bi2Se3 (AgxBi2−xSe3) shows insulating behavior above 35 K, but below 35 K, ρ suddenly decreases with decreasing temperature, in contrast to the metallic behavior for non-doped Bi2Se3 at 1.5–300 K. This significant change in transport properties from metallic behavior clearly shows that the Ag doping of Bi2Se3 can effectively tune the Fermi level downward. The Hall effect measurement shows that carrier is still electron in AgxBi2−xSe3 and the electron density changes with temperature to reasonably explain the transport properties. Furthermore, the positive gating of AgxBi2−xSe3 provides metallic behavior that is similar to that of non-doped Bi2Se3, indicating a successful upward tuning of the Fermi level.
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Tian W, Yu W, Shi J, Wang Y. The Property, Preparation and Application of Topological Insulators: A Review. MATERIALS (BASEL, SWITZERLAND) 2017; 10:E814. [PMID: 28773173 PMCID: PMC5551857 DOI: 10.3390/ma10070814] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 07/09/2017] [Accepted: 07/10/2017] [Indexed: 01/14/2023]
Abstract
Topological insulator (TI), a promising quantum and semiconductor material, has gapless surface state and narrow bulk band gap. Firstly, the properties, classifications and compounds of TI are introduced. Secondly, the preparation and doping of TI are assessed. Some results are listed. (1) Although various preparation methods are used to improve the crystal quality of the TI, it cannot reach the industrialization. Fermi level regulation still faces challenges; (2) The carrier type and lattice of TI are affected by non-magnetic impurities. The most promising property is the superconductivity at low temperature; (3) Magnetic impurities can destroy the time-reversal symmetry of the TI surface, which opens the band gap on the TI surface resulting in some novel physical effects such as quantum anomalous Hall effect (QAHE). Thirdly, this paper summarizes various applications of TI including photodetector, magnetic device, field-effect transistor (FET), laser, and so on. Furthermore, many of their parameters are compared based on TI and some common materials. It is found that TI-based devices exhibit excellent performance, but some parameters such as signal to noise ratio (S/N) are still lower than other materials. Finally, its advantages, challenges and future prospects are discussed. Overall, this paper provides an opportunity to improve crystal quality, doping regulation and application of TI.
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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.
| | - Jing Shi
- 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.
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