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Li S, Gong M, Li YH, Jiang H, Xie XC. High spin axion insulator. Nat Commun 2024; 15:4250. [PMID: 38762497 PMCID: PMC11102527 DOI: 10.1038/s41467-024-48542-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 05/03/2024] [Indexed: 05/20/2024] Open
Abstract
Axion insulators possess a quantized axion field θ = π protected by combined lattice and time-reversal symmetry, holding great potential for device applications in layertronics and quantum computing. Here, we propose a high-spin axion insulator (HSAI) defined in large spin-s representation, which maintains the same inherent symmetry but possesses a notable axion field θ = (s + 1/2)2π. Such distinct axion field is confirmed independently by the direct calculation of the axion term using hybrid Wannier functions, layer-resolved Chern numbers, as well as the topological magneto-electric effect. We show that the guaranteed gapless quasi-particle excitation is absent at the boundary of the HSAI despite its integer surface Chern number, hinting an unusual quantum anomaly violating the conventional bulk-boundary correspondence. Furthermore, we ascertain that the axion field θ can be precisely tuned through an external magnetic field, enabling the manipulation of bonded transport properties. The HSAI proposed here can be experimentally verified in ultra-cold atoms by the quantized non-reciprocal conductance or topological magnetoelectric response. Our work enriches the understanding of axion insulators in condensed matter physics, paving the way for future device applications.
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Affiliation(s)
- Shuai Li
- School of Physical Science and Technology, Soochow University, Suzhou, 215006, China
- Institute for Advanced Study, Soochow University, Suzhou, 215006, China
| | - Ming Gong
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Yu-Hang Li
- School of Physics, Nankai University, Tianjin, 300071, China.
| | - Hua Jiang
- Institute for Advanced Study, Soochow University, Suzhou, 215006, China.
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai, 200433, China.
- Interdisciplinary Center for Theoretical Physics and Information Sciences (ICTPIS), Fudan University, Shanghai, 200433, China.
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai, 200433, China
- Interdisciplinary Center for Theoretical Physics and Information Sciences (ICTPIS), Fudan University, Shanghai, 200433, China
- Hefei National Laboratory, Hefei, 230088, China
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2
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Li H, Jiang H, Sun QF, Xie XC. Emergent energy dissipation in quantum limit. Sci Bull (Beijing) 2024; 69:1221-1227. [PMID: 38548568 DOI: 10.1016/j.scib.2024.03.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/29/2024] [Accepted: 03/06/2024] [Indexed: 05/06/2024]
Abstract
Energy dissipation is of fundamental interest and crucial importance in quantum systems. However, whether energy dissipation can emerge without backscattering inside topological systems remains a question. As a hallmark, we propose a microscopic picture that illustrates energy dissipation in the quantum Hall (QH) plateau regime of graphene. Despite the quantization of Hall, longitudinal, and two-probe resistances (dubbed as the quantum limit), we find that the energy dissipation emerges in the form of Joule heat. It is demonstrated that the non-equilibrium energy distribution of carriers plays much more essential roles than the resistance on energy dissipation. Eventually, we suggest probing the phenomenon by measuring local temperature increases in experiments and reconsidering the dissipation typically ignored in realistic topological circuits.
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Affiliation(s)
- Hailong Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Hua Jiang
- Interdisciplinary Center for Theoretical Physics and Information Sciences (ICTPIS), Fudan University, Shanghai 200433, China; Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China.
| | - Qing-Feng Sun
- 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; Hefei National Laboratory, Hefei 230088, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Interdisciplinary Center for Theoretical Physics and Information Sciences (ICTPIS), Fudan University, Shanghai 200433, China; Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Hefei National Laboratory, Hefei 230088, China.
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3
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Chen R, Sun HP, Gu M, Hua CB, Liu Q, Lu HZ, Xie XC. Layer Hall effect induced by hidden Berry curvature in antiferromagnetic insulators. Natl Sci Rev 2024; 11:nwac140. [PMID: 38264341 PMCID: PMC10804226 DOI: 10.1093/nsr/nwac140] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 01/25/2024] Open
Abstract
The layer Hall effect describes electrons spontaneously deflected to opposite sides at different layers, which has been experimentally reported in the MnBi2Te4 thin films under perpendicular electric fields. Here, we reveal a universal origin of the layer Hall effect in terms of the so-called hidden Berry curvature, as well as material design principles. Hence, it gives rise to zero Berry curvature in momentum space but non-zero layer-locked hidden Berry curvature in real space. We show that, compared to that of a trivial insulator, the layer Hall effect is significantly enhanced in antiferromagnetic topological insulators. Our universal picture provides a paradigm for revealing the hidden physics as a result of the interplay between the global and local symmetries, and can be generalized in various scenarios.
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Affiliation(s)
- Rui Chen
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
| | - Hai-Peng Sun
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, Würzburg 97074, Germany
| | - Mingqiang Gu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Chun-Bo Hua
- School of Electronic and Information Engineering, Hubei University of Science and Technology, Xianning 437100, China
| | - Qihang Liu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Computational Science and Material Design, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C 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
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4
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Li S, Liu T, Liu C, Wang Y, Lu HZ, Xie XC. Progress on the antiferromagnetic topological insulator MnBi 2Te 4. Natl Sci Rev 2024; 11:nwac296. [PMID: 38213528 PMCID: PMC10776361 DOI: 10.1093/nsr/nwac296] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 10/18/2022] [Accepted: 11/09/2022] [Indexed: 01/13/2024] Open
Abstract
Topological materials, which feature robust surface and/or edge states, have now been a research focus in condensed matter physics. They represent a new class of materials exhibiting nontrivial topological phases, and provide a platform for exploring exotic transport phenomena, such as the quantum anomalous Hall effect and the quantum spin Hall effect. Recently, magnetic topological materials have attracted considerable interests due to the possibility to study the interplay between topological and magnetic orders. In particular, the quantum anomalous Hall and axion insulator phases can be realized in topological insulators with magnetic order. MnBi2Te4, as the first intrinsic antiferromagnetic topological insulator discovered, allows the examination of existing theoretical predictions; it has been extensively studied, and many new discoveries have been made. Here we review the progress made on MnBi2Te4 from both experimental and theoretical aspects. The bulk crystal and magnetic structures are surveyed first, followed by a review of theoretical calculations and experimental probes on the band structure and surface states, and a discussion of various exotic phases that can be realized in MnBi2Te4. The properties of MnBi2Te4 thin films and the corresponding transport studies are then reviewed, with an emphasis on the edge state transport. Possible future research directions in this field are also discussed.
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Affiliation(s)
- Shuai Li
- Department of Physics, Harbin Institute of Technology, Harbin 150001, China
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen 518045, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
| | - Tianyu Liu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen 518045, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
| | - Chang Liu
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing 100872, China
| | - Yayu Wang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
- Hefei National Laboratory, Hefei 230088, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen 518045, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Hefei National Laboratory, Hefei 230088, China
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5
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Wang H, Liu Y, Gong M, Jiang H, Gao X, Ma W, Luo J, Ji H, Ge J, Jia S, Gao P, Wang Z, Xie XC, Wang J. Emergent superconductivity in topological-kagome-magnet/metal heterostructures. Nat Commun 2023; 14:6998. [PMID: 37919274 PMCID: PMC10622413 DOI: 10.1038/s41467-023-42779-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 10/20/2023] [Indexed: 11/04/2023] Open
Abstract
Itinerant kagome lattice magnets exhibit many novel correlated and topological quantum electronic states with broken time-reversal symmetry. Superconductivity, however, has not been observed in this class of materials, presenting a roadblock in a promising path toward topological superconductivity. Here, we report that novel superconductivity can emerge at the interface of kagome Chern magnet TbMn6Sn6 and metal heterostructures when elemental metallic thin films are deposited on either the top (001) surface or the side surfaces. Superconductivity is also successfully induced and systematically studied by using various types of metallic tips on different TbMn6Sn6 surfaces in point-contact measurements. The anisotropy of the superconducting upper critical field suggests that the emergent superconductivity is quasi-two-dimensional. Remarkably, the interface superconductor couples to the magnetic order of the kagome metal and exhibits a hysteretic magnetoresistance in the superconducting states. Taking into account the spin-orbit coupling, the observed interface superconductivity can be a surprising and more realistic realization of the p-wave topological superconductors theoretically proposed for two-dimensional semiconductors proximity-coupled to s-wave superconductors and insulating ferromagnets. Our findings of robust superconductivity in topological-Chern-magnet/metal heterostructures offer a new direction for investigating spin-triplet pairing and topological superconductivity.
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Affiliation(s)
- He Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Center for Quantum Physics and Intelligent Sciences, Department of Physics, Capital Normal University, Beijing, 100048, China
| | - Yanzhao Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Ming Gong
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Hua Jiang
- Institute for Advanced Study, Soochow University, Suzhou, 215006, China
| | - Xiaoyue Gao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Wenlong Ma
- 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
| | - Haoran Ji
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Jun Ge
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Shuang Jia
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Peng Gao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill, MA, 02467, USA.
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Hefei National Laboratory, Hefei, 230088, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai, 200433, China
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
- Hefei National Laboratory, Hefei, 230088, China.
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China.
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6
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Ma N, Qiang XB, Xie Z, Zhang Y, Yan S, Cao S, Wang P, Zhang L, Gu GD, Li Q, Xie XC, Lu HZ, Wei X, Chen JH. Perpendicular in-plane negative magnetoresistance in ZrTe 5. Sci Bull (Beijing) 2023:S2095-9273(23)00393-6. [PMID: 37402602 DOI: 10.1016/j.scib.2023.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/22/2023] [Accepted: 06/15/2023] [Indexed: 07/06/2023]
Affiliation(s)
- Ning Ma
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, Beijing 100871, China
| | - Xiao-Bin Qiang
- Department of Physics and Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhijian Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Yu Zhang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Shili Yan
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Shimin Cao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Peipei Wang
- Department of Physics and Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Liyuan Zhang
- Department of Physics and Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - G D Gu
- Condensed Matter Physics & Materials Science Division, Brookhaven National Laboratory, Upton, NY 11973-5000, USA
| | - Qiang Li
- Condensed Matter Physics & Materials Science Division, Brookhaven National Laboratory, Upton, NY 11973-5000, USA; Department of Physics and Astronomy, Stony Brook, University, Stony Brook, NY 11794-3800, USA
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Hefei National Laboratory, Hefei 230088, China
| | - Hai-Zhou Lu
- Department of Physics and Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Xinjian Wei
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Beijing Academy of Quantum Information Sciences, Beijing 100193, China.
| | - Jian-Hao Chen
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, Beijing 100871, China; Beijing Academy of Quantum Information Sciences, Beijing 100193, China; Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China.
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7
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Zhao PL, Qiang XB, Lu HZ, Xie XC. Zhao et al. Reply. Phys Rev Lett 2023; 130:219702. [PMID: 37295096 DOI: 10.1103/physrevlett.130.219702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 04/21/2023] [Indexed: 06/12/2023]
Affiliation(s)
- Peng-Lu Zhao
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Xiao-Bin Qiang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen 518045, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen 518045, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Hefei National Laboratory, Hefei 230088, China
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8
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Qi S, Chen D, Chen K, Liu J, Chen G, Luo B, Cui H, Jia L, Li J, Huang M, Song Y, Han S, Tong L, Yu P, Liu Y, Wu H, Wu S, Xiao J, Shindou R, Xie XC, Chen JH. Giant electrically tunable magnon transport anisotropy in a van der Waals antiferromagnetic insulator. Nat Commun 2023; 14:2526. [PMID: 37130859 PMCID: PMC10154397 DOI: 10.1038/s41467-023-38172-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 04/19/2023] [Indexed: 05/04/2023] Open
Abstract
Anisotropy is a manifestation of lowered symmetry in material systems that have profound fundamental and technological implications. For van der Waals magnets, the two-dimensional (2D) nature greatly enhances the effect of in-plane anisotropy. However, electrical manipulation of such anisotropy as well as demonstration of possible applications remains elusive. In particular, in-situ electrical modulation of anisotropy in spin transport, vital for spintronics applications, has yet to be achieved. Here, we realized giant electrically tunable anisotropy in the transport of second harmonic thermal magnons (SHM) in van der Waals anti-ferromagnetic insulator CrPS4 with the application of modest gate current. Theoretical modeling found that 2D anisotropic spin Seebeck effect is the key to the electrical tunability. Making use of such large and tunable anisotropy, we demonstrated multi-bit read-only memories (ROMs) where information is inscribed by the anisotropy of magnon transport in CrPS4. Our result unveils the potential of anisotropic van der Waals magnons for information storage and processing.
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Affiliation(s)
- Shaomian Qi
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Di Chen
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Kangyao Chen
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Jianqiao Liu
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Guangyi Chen
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Bingcheng Luo
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Hang Cui
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Linhao Jia
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Jiankun Li
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Miaoling Huang
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Yuanjun Song
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Shiyi Han
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Lianming Tong
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Peng Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - Yi Liu
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing, China
| | - Hongyu Wu
- Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China
| | - Shiwei Wu
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai, China
| | - Jiang Xiao
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai, China
| | - Ryuichi Shindou
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - X C Xie
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
- Hefei National Laboratory, Hefei, China
| | - Jian-Hao Chen
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China.
- Beijing Academy of Quantum Information Sciences, Beijing, China.
- Hefei National Laboratory, Hefei, China.
- Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, Beijing, China.
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9
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Yan J, Wu Y, Yuan S, Liu X, Pfeiffer LN, West KW, Liu Y, Fu H, Xie XC, Lin X. Anomalous quantized plateaus in two-dimensional electron gas with gate confinement. Nat Commun 2023; 14:1758. [PMID: 36997525 PMCID: PMC10064851 DOI: 10.1038/s41467-023-37495-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 03/16/2023] [Indexed: 04/01/2023] Open
Abstract
AbstractQuantum information can be coded by the topologically protected edges of fractional quantum Hall (FQH) states. Investigation on FQH edges in the hope of searching and utilizing non-Abelian statistics has been a focused challenge for years. Manipulating the edges, e.g. to bring edges close to each other or to separate edges spatially, is a common and essential step for such studies. The FQH edge structures in a confined region are typically presupposed to be the same as that in the open region in analysis of experimental results, but whether they remain unchanged with extra confinement is obscure. In this work, we present a series of unexpected plateaus in a confined single-layer two-dimensional electron gas (2DEG), which are quantized at anomalous fractions such as 9/4, 17/11, 16/13 and the reported 3/2. We explain all the plateaus by assuming surprisingly larger filling factors in the confined region. Our findings enrich the understanding of edge states in the confined region and in the applications of gate manipulation, which is crucial for the experiments with quantum point contact and interferometer.
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10
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Zhang ZQ, Liu H, Liu H, Jiang H, Xie XC. Bulk-boundary correspondence in disordered non-Hermitian systems. Sci Bull (Beijing) 2023; 68:157-164. [PMID: 36653216 DOI: 10.1016/j.scib.2023.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/15/2022] [Accepted: 12/28/2022] [Indexed: 01/07/2023]
Abstract
The bulk-boundary correspondence (BBC) refers to the consistency between eigenvalues calculated under open and periodic boundary conditions. This consistency can be destroyed in systems with non-Hermitian skin effect (NHSE). In spite of the great success of the generalized Brillouin zone (GBZ) theory in clean non-Hermitian systems, the applicability of GBZ theory is questionable when the translational symmetry is broken. Thus, it is of great value to rebuild the BBC for disordered samples, which extends the application of GBZ theory in non-Hermitian systems. Here, we propose a scheme to reconstruct BBC, which can be regarded as the solution of an optimization problem. By solving the optimization problem analytically, we reconstruct the BBC and obtain the modified GBZ theory in several prototypical disordered non-Hermitian models. The modified GBZ theory provides a precise description of the fantastic NHSE, which predicts the asynchronous-disorder-reversed NHSE's directions.
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Affiliation(s)
- Zhi-Qiang Zhang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China; Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - Hongfang Liu
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China; Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China; Institute for Advanced Study, Soochow University, Suzhou 215006, China.
| | - X C Xie
- 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
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11
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Zhou H, Li H, Xu DH, Chen CZ, Sun QF, Xie XC. Transport Theory of Half-Quantized Hall Conductance in a Semimagnetic Topological Insulator. Phys Rev Lett 2022; 129:096601. [PMID: 36083672 DOI: 10.1103/physrevlett.129.096601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Recently, a half-quantized Hall conductance (HQHC) plateau was experimentally observed in a semimagnetic topological insulator heterostructure. However, the heterostructure was metallic with a nonzero longitudinal conductance, which contradicts the common belief that quantized Hall conductance is usually observed in insulators. In this work, we systematically study the surface transport of a semimagnetic topological insulator with both gapped and gapless Dirac surfaces in the presence of dephasing process. In particular, we reveal that the HQHC is directly related to the half-quantized chiral current along the edge of a strongly dephasing metal. The Hall conductance keeps a half-quantized value for large dephasing strengths, while the longitudinal conductance varies with Fermi energies and dephasing strengths. Furthermore, we evaluate both the conductance and resistance as a function of the temperature, which is consistent with the experimental results. Our results not only provide the microscopic transport mechanism of the HQHC, but also are instructive for the probe of the HQHC in future experiments.
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Affiliation(s)
- Humian Zhou
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Hailong Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Dong-Hui Xu
- Department of Physics, and Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, China
- Center of Quantum Materials and Devices, Chongqing University, Chongqing 400044, China
| | - Chui-Zhen Chen
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - Qing-Feng Sun
- 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
| | - X C 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
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12
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Wang M, Liu H, Xie XC. New Type of Anticommutative Dynamical Magnetoelectric Response. Phys Rev Lett 2022; 128:236601. [PMID: 35749168 DOI: 10.1103/physrevlett.128.236601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 03/24/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Axion field induced topological magnetoelectric response has attracted lots of attention since it was first proposed by Qi et al. [Phys. Rev. B 78, 195424 (2008).PRBMDO1098-012110.1103/PhysRevB.78.195424]. Here we find a new type of anticommutative magnetoelectric response β^{ξ}(ω), which can induce a dynamical magnetoelectric current driven by a time-varying magnetic field. Unlike the Chern-Simons axion term, this magnetoelectric response term is gauge independent and nonquantized, and manifests in the systems breaking the symmetries of the time reversal, inversion, and mirror. In particular, we propose the antiferromagnetic material Mn_{2}Bi_{2}Te_{5} as a material candidate to observe dynamical magnetoelectric current, in which a large magnetoelectric response term β^{ξ}(ω) originates from band inversion.
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Affiliation(s)
- Maoyuan Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100871, China
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13
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Wu Y, Jiang H, Chen H, Liu H, Liu J, Xie XC. Non-Abelian Braiding in Spin Superconductors Utilizing the Aharonov-Casher Effect. Phys Rev Lett 2022; 128:106804. [PMID: 35333073 DOI: 10.1103/physrevlett.128.106804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/16/2021] [Accepted: 02/04/2022] [Indexed: 06/14/2023]
Abstract
Spin superconductor (SSC) is an exciton condensate state where the spin-triplet exciton superfluidity is charge neutral while spin 2(ℏ/2). In analogy to the Majorana zero mode (MZM) in topological superconductors, the interplay between SSC and band topology will also give rise to a specific kind of topological bound state obeying non-Abelian braiding statistics. Remarkably, the non-Abelian geometric phase here originates from the Aharonov-Casher effect of the "half-charge" other than the Aharonov-Bohm effect. Such topological bound state of SSC is bound with the vortex of electric flux gradient and can be experimentally more distinct than the MZM for being electrically charged. This theoretical proposal provides a new avenue investigating the non-Abelian braiding physics without the assistance of MZM and charge superconductor.
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Affiliation(s)
- Yijia Wu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - Hua Chen
- Department of Physics, Zhejiang Normal University, Jinhua 321004, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Jie Liu
- Department of Applied Physics, School of Science, Xian Jiaotong University, Xian 710049, China
| | - X C Xie
- 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
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14
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Li H, Chen CZ, Jiang H, Xie XC. Coexistence of Quantum Hall and Quantum Anomalous Hall Phases in Disordered MnBi_{2}Te_{4}. Phys Rev Lett 2021; 127:236402. [PMID: 34936771 DOI: 10.1103/physrevlett.127.236402] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 11/04/2021] [Indexed: 06/14/2023]
Abstract
In most cases, to observe quantized Hall plateaus, an external magnetic field is applied in intrinsic magnetic topological insulators MnBi_{2}Te_{4}. Nevertheless, whether the nonzero Chern number (C≠0) phase is a quantum anomalous Hall (QAH) state, or a quantum Hall (QH) state, or a mixing state of both is still a puzzle, especially for the recently observed C=2 phase [Deng et al., Science 367, 895 (2020)SCIEAS0036-807510.1126/science.aax8156]. In this Letter, we propose a physical picture based on the Anderson localization to understand the observed Hall plateaus in disordered MnBi_{2}Te_{4}. Rather good consistency between the experimental and numerical results confirms that the bulk states are localized in the absence of a magnetic field and a QAH edge state emerges with C=1. However, under a strong magnetic field, the lowest Landau band formed with the localized bulk states, survives disorder, together with the QAH edge state, leading to a C=2 phase. Eventually, we present a phase diagram of a disordered MnBi_{2}Te_{4} which indicates more coexistence states of QAH and QH to be verified by future experiments.
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Affiliation(s)
- Hailong Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Chui-Zhen Chen
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - X C Xie
- 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
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15
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Cai R, Yao Y, Lv P, Ma Y, Xing W, Li B, Ji Y, Zhou H, Shen C, Jia S, Xie XC, Žutić I, Sun QF, Han W. Evidence for anisotropic spin-triplet Andreev reflection at the 2D van der Waals ferromagnet/superconductor interface. Nat Commun 2021; 12:6725. [PMID: 34795286 PMCID: PMC8602320 DOI: 10.1038/s41467-021-27041-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 11/01/2021] [Indexed: 11/08/2022] Open
Abstract
Fundamental symmetry breaking and relativistic spin-orbit coupling give rise to fascinating phenomena in quantum materials. Of particular interest are the interfaces between ferromagnets and common s-wave superconductors, where the emergent spin-orbit fields support elusive spin-triplet superconductivity, crucial for superconducting spintronics and topologically-protected Majorana bound states. Here, we report the observation of large magnetoresistances at the interface between a quasi-two-dimensional van der Waals ferromagnet Fe0.29TaS2 and a conventional s-wave superconductor NbN, which provides the possible experimental evidence for the spin-triplet Andreev reflection and induced spin-triplet superconductivity at ferromagnet/superconductor interface arising from Rashba spin-orbit coupling. The temperature, voltage, and interfacial barrier dependences of the magnetoresistance further support the induced spin-triplet superconductivity and spin-triplet Andreev reflection. This discovery, together with the impressive advances in two-dimensional van der Waals ferromagnets, opens an important opportunity to design and probe superconducting interfaces with exotic properties.
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Affiliation(s)
- Ranran Cai
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
| | - Yunyan Yao
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
| | - Peng Lv
- Department of Physics, Wuhan University of Technology, 430070, Wuhan, China
| | - Yang Ma
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
| | - Wenyu Xing
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
| | - Boning Li
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
| | - Yuan Ji
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
| | - Huibin Zhou
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
| | - Chenghao Shen
- Department of Physics, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Shuang Jia
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, 100190, Beijing, P. R. China
- Beijing Academy of Quantum Information Sciences, 100193, Beijing, P. R. China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, 100190, Beijing, P. R. China
- Beijing Academy of Quantum Information Sciences, 100193, Beijing, P. R. China
| | - Igor Žutić
- Department of Physics, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Qing-Feng Sun
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, 100190, Beijing, P. R. China
- Beijing Academy of Quantum Information Sciences, 100193, Beijing, P. R. China
| | - Wei Han
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, P. R. China.
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, P. R. China.
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16
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Zhao PL, Qiang XB, Lu HZ, Xie XC. Coulomb Instabilities of a Three-Dimensional Higher-Order Topological Insulator. Phys Rev Lett 2021; 127:176601. [PMID: 34739297 DOI: 10.1103/physrevlett.127.176601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Topological insulators (TIs) are an exciting discovery because of their robustness against disorder and interactions. Recently, second-order TIs have been attracting increasing attention, because they host topologically protected 1D hinge states in 3D or 0D corner states in 2D. A significantly critical issue is whether the second-order TIs also survive interactions, but it is still unexplored. We study the effects of weak Coulomb interactions on a 3D second-order TI, with the help of renormalization-group calculations. We find that the 3D second-order TIs are always unstable, suffering from two types of topological phase transitions. One is from second-order TI to TI, the other is to normal insulator. The first type is accompanied by emergent time-reversal and inversion symmetries and has a dynamical critical exponent κ=1. The second type does not have the emergent symmetries but has nonuniversal dynamical critical exponents κ<1. Our results may inspire more inspections on the stability of higher-order topological states of matter and related novel quantum criticalities.
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Affiliation(s)
- Peng-Lu Zhao
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Xiao-Bin Qiang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- 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, West Building 3, No. 10, Xibeiwang East Road, Haidian District, Beijing 100193, China
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17
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Huang C, Zhang E, Zhang Y, Zhang J, Xiu F, Liu H, Xie X, Ai L, Yang Y, Zhao M, Qi J, Li L, Liu S, Li Z, Zhan R, Bie YQ, Kou X, Deng S, Xie XC. Observation of thickness-tuned universality class in superconducting β-W thin films. Sci Bull (Beijing) 2021; 66:1830-1838. [PMID: 36654392 DOI: 10.1016/j.scib.2021.05.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/23/2021] [Accepted: 05/24/2021] [Indexed: 01/20/2023]
Abstract
The interplay between quenched disorder and critical behavior in quantum phase transitions is conceptually fascinating and of fundamental importance for understanding phase transitions. However, it is still unclear whether or not the quenched disorder influences the universality class of quantum phase transitions. More crucially, the absence of superconducting-metal transitions under in-plane magnetic fields in 2D superconductors imposes constraints on the universality of quantum criticality. Here, we observe the thickness-tuned universality class of superconductor-metal transition by changing the disorder strength in β-W films with varying thickness. The finite-size scaling uncovers the switch of universality class: quantum Griffiths singularity to multiple quantum criticality at a critical thickness of tc⊥1~8nm and then from multiple quantum criticality to single criticality at tc⊥2~16nm. Moreover, the superconducting-metal transition is observed for the first time under in-plane magnetic fields and the universality class is changed at tc‖~8nm. The observation of thickness-tuned universality class under both out-of-plane and in-plane magnetic fields provides broad information for the disorder effect on superconducting-metal transitions and quantum criticality.
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Affiliation(s)
- Ce Huang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Enze Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Yong Zhang
- School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jinglei Zhang
- Anhui Province Key Laboratory of Condensed Matter Physics at ExtremeConditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Faxian Xiu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China; Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China; Shanghai Research Center for Quantum Sciences, Shanghai 201315, China.
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China.
| | - Xiaoyi Xie
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Linfeng Ai
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Yunkun Yang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Minhao Zhao
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Junjie Qi
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Lun Li
- School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Shanshan Liu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Zihan Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Runze Zhan
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Ya-Qing Bie
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Xufeng Kou
- School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Shaozhi Deng
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - X C Xie
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China; 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
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18
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Liu Y, Qi S, Fang J, Sun J, Liu C, Liu Y, Qi J, Xing Y, Liu H, Lin X, Wang L, Xue QK, Xie XC, Wang J. Observation of In-Plane Quantum Griffiths Singularity in Two-Dimensional Crystalline Superconductors. Phys Rev Lett 2021; 127:137001. [PMID: 34623853 DOI: 10.1103/physrevlett.127.137001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/27/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Quantum Griffiths singularity (QGS) reveals the profound influence of quenched disorder on the quantum phase transitions, characterized by the divergence of the dynamical critical exponent at the boundary of the vortex glasslike phase, named as quantum Griffiths phase. However, in the absence of vortices, whether the QGS can exist under a parallel magnetic field remains a puzzle. Here, we study the magnetic field induced superconductor-metal transition in ultrathin crystalline PdTe_{2} films grown by molecular beam epitaxy. Remarkably, the QGS emerges under both perpendicular and parallel magnetic field in four-monolayer PdTe_{2} films. The direct activated scaling analysis with a new irrelevant correction has been proposed, providing important evidence of QGS. With increasing film thickness to six monolayers, the QGS disappears under perpendicular field but persists under parallel field, and this discordance may originate from the differences in microscopic processes. Our work demonstrates the universality of parallel field induced QGS and can stimulate further investigations on novel quantum phase transitions under parallel magnetic field.
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Affiliation(s)
- Yi Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Department of Physics, Renmin University of China, Beijing 100872, China
| | - Shichao Qi
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Jingchao Fang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Jian Sun
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Chong Liu
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yanzhao Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Junjie Qi
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Ying Xing
- Department of Materials Science and Engineering, College of New Energy and Materials, China University of Petroleum, Beijing 102249, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Xi Lin
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Lili Wang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Qi-Kun Xue
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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19
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Abstract
The nonlinear Hall effect is an unconventional response, in which a voltage can be driven by two perpendicular currents in the Hall-bar measurement. Unprecedented in the family of the Hall effects, it can survive time-reversal symmetry but is sensitive to the breaking of discrete and crystal symmetries. It is a quantum transport phenomenon that has deep connection with the Berry curvature. However, a full quantum description is still absent. Here we construct a quantum theory of the nonlinear Hall effect by using the diagrammatic technique. Quite different from nonlinear optics, nearly all the diagrams account for the disorder effects, which play decisive role in the electronic transport. After including the disorder contributions in terms of the Feynman diagrams, the total nonlinear Hall conductivity is enhanced but its sign remains unchanged for the 2D tilted Dirac model, compared to the one with only the Berry curvature contribution. We discuss the symmetry of the nonlinear conductivity tensor and predict a pure disorder-induced nonlinear Hall effect for point groups C3, C3h, C3v, D3h, D3 in 2D, and T, Td, C3h, D3h in 3D. This work will be helpful for explorations of the topological physics beyond the linear regime.
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Affiliation(s)
- Z Z Du
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, China
| | - C M Wang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, China
- Department of Physics, Shanghai Normal University, Shanghai, China
| | - Hai-Peng Sun
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China.
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, China.
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China
- Beijing Academy of Quantum Information Sciences, Beijing, China
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20
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Chen R, Liu T, Wang CM, Lu HZ, Xie XC. Field-Tunable One-Sided Higher-Order Topological Hinge States in Dirac Semimetals. Phys Rev Lett 2021; 127:066801. [PMID: 34420339 DOI: 10.1103/physrevlett.127.066801] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
Recently, higher-order topological matter and 3D quantum Hall effects have attracted a great amount of attention. The Fermi-arc mechanism of the 3D quantum Hall effect proposed to exist in Weyl semimetals is characterized by the one-sided hinge states, which do not exist in all the previous quantum Hall systems, and more importantly, pose a realistic example of the higher-order topological matter. The experimental effort so far is in the Dirac semimetal Cd_{3}As_{2}, where, however, time-reversal symmetry leads to hinge states on both sides of the top and bottom surfaces, instead of the aspired one-sided hinge states. We propose that under a tilted magnetic field, the hinge states in Cd_{3}As_{2}-like Dirac semimetals can be one sided, highly tunable by field direction and Fermi energy, and robust against weak disorder. Furthermore, we propose a scanning tunneling Hall measurement to detect the one-sided hinge states. Our results will be insightful for exploring not only the quantum Hall effects beyond two dimensions, but also other higher-order topological insulators in the future.
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Affiliation(s)
- Rui Chen
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- School of Physics, Southeast University, Nanjing 211189, China
| | - Tianyu Liu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Max-Planck-Institut für Physik komplexer Systeme, 01187 Dresden, Germany
| | - C M Wang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- Department of Physics, Shanghai Normal University, Shanghai 200234, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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21
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Zhao PL, Lu HZ, Xie XC. Theory for Magnetic-Field-Driven 3D Metal-Insulator Transitions in the Quantum Limit. Phys Rev Lett 2021; 127:046602. [PMID: 34355953 DOI: 10.1103/physrevlett.127.046602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/07/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Metal-insulator transitions driven by magnetic fields have been extensively studied in 2D, but a 3D theory is still lacking. Motivated by recent experiments, we develop a scaling theory for the metal-insulator transitions in the strong-magnetic-field quantum limit of a 3D system. By using a renormalization-group calculation to treat electron-electron interactions, electron-phonon interactions, and disorder on the same footing, we obtain the critical exponent that characterizes the scaling relations of the resistivity to temperature and magnetic field. By comparing the critical exponent with those in a recent experiment [F. Tang et al., Nature (London) 569, 537 (2019)NATUAS0028-083610.1038/s41586-019-1180-9], we conclude that the insulating ground state was not only a charge-density wave driven by electron-phonon interactions but also coexisting with strong electron-electron interactions and backscattering disorder. We also propose a current-scaling experiment for further verification. Our theory will be helpful for exploring the emergent territory of 3D metal-insulator transitions under strong magnetic fields.
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Affiliation(s)
- Peng-Lu Zhao
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- 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, West Building 3, No. 10, Xibeiwang East Road, Haidian District, Beijing 100193, China
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22
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Zeng J, Lu M, Liu H, Jiang H, Xie XC. Realistic flat-band model based on degenerate p-orbitals in two-dimensional ionic materials. Sci Bull (Beijing) 2021; 66:765-770. [PMID: 36654133 DOI: 10.1016/j.scib.2021.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 12/23/2020] [Accepted: 01/07/2021] [Indexed: 01/20/2023]
Abstract
Though several theoretical models have been proposed to design electronic flat-bands, the definite experimental realization in two-dimensional atomic crystal is still lacking. Here we propose a novel and realistic flat-band model based on threefold degenerate p-orbitals in two-dimensional ionic materials. Our theoretical analysis and first-principles calculations show that the proposed flat-band can be realized in 1T layered materials of alkali-metal chalogenides and metal-carbon group compounds. Some of the former are theoretically predicted to be stable as layered materials (e.g., K2S), and some of the latter have been experimentally fabricated in previous works (e.g., Gd2CCl2). More interestingly, the flat-band is partially filled in the heterostructure of a K2S monolayer and graphene layers. The spin polarized nearly flat-band can be realized in the ferromagnetic state of a Gd2CCl2 monolayer, which has been fabricated in experiments. Our theoretical model together with the material predictions provide a realistic platform for the study of flat-bands and related exotic quantum phases.
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Affiliation(s)
- Jiang Zeng
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
| | - Ming Lu
- Beijing Academy of Quantum Information Sciences, Beijing 100871, China; International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Beijing Academy of Quantum Information Sciences, Beijing 100193, China; CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100871, China
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23
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Li H, Jiang H, Chen CZ, Xie XC. Critical Behavior and Universal Signature of an Axion Insulator State. Phys Rev Lett 2021; 126:156601. [PMID: 33929241 DOI: 10.1103/physrevlett.126.156601] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Recently, the search for an axion insulator state in the ferromagnetic-3D topological insulator (TI) heterostructure and MnBi_{2}Te_{4} has attracted intense interest. However, its detection remains difficult in experiments. We systematically investigate the disorder-induced phase transition of the axion insulator state in a 3D TI with antiparallel magnetization alignment surfaces. It is found that there exists a 2D disorder-induced phase transition on the surfaces of the 3D TI which shares the same universality class with the quantum Hall plateau to plateau transition. Then, we provide a phenomenological theory which maps the random mass Dirac Hamiltonian of the axion insulator state into the Chalker-Coddington network model. Therefore, we propose probing the axion insulator state by investigating the universal signature of such a phase transition in the ferromagnetic-3D TI heterostructure and MnBi_{2}Te_{4}. Our findings not only show a global phase diagram of the axion insulator state, but also stimulate further experiments to probe it.
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Affiliation(s)
- Hailong Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - Chui-Zhen Chen
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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24
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Ma Z, Li S, Zheng YW, Xiao MM, Jiang H, Gao JH, Xie XC. Topological flat bands in twisted trilayer graphene. Sci Bull (Beijing) 2021; 66:18-22. [PMID: 36654307 DOI: 10.1016/j.scib.2020.10.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 01/20/2023]
Abstract
Twisted trilayer graphene (TLG) may be the simplest realistic system so far, which has flat bands with nontrivial topology. Here, we give a comprehensive calculation about its band structures and the band topology, i.e., valley Chern number of the nearly flat bands, with the continuum model. With realistic parameters, the magic angle of twisted TLG is about 1.12°, at which two nearly flat bands appears. Unlike the twisted bilayer graphene, a small twist angle can induce a tiny gap at all the Dirac points, which can be enlarged further by a perpendicular electric field. The valley Chern numbers of the two nearly flat bands in the twisted TLG depends on the twist angle θ and the perpendicular electric field E⊥. Considering its topological flat bands, the twisted TLG should be an ideal experimental platform to study the strongly correlated physics in topologically nontrivial flat band systems. And, due to its reduced symmetry, the correlated states in twisted TLG should be quite different from that in twisted bilayer graphene and twisted double bilayer graphene.
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Affiliation(s)
- Zhen Ma
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shuai Li
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ya-Wen Zheng
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Meng-Meng Xiao
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Jin-Hua Gao
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - X C 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
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25
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Ge J, Ma D, Liu Y, Wang H, Li Y, Luo J, Luo T, Xing Y, Yan J, Mandrus D, Liu H, Xie XC, Wang J. Unconventional Hall effect induced by Berry curvature. Natl Sci Rev 2020; 7:1879-1885. [PMID: 34691529 PMCID: PMC8288766 DOI: 10.1093/nsr/nwaa163] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/15/2020] [Accepted: 07/08/2020] [Indexed: 11/14/2022] Open
Abstract
Berry phase and Berry curvature play a key role in the development of topology in physics and do contribute to the transport properties in solid state systems. In this paper, we report the finding of novel nonzero Hall effect in topological material ZrTe5 flakes when the in-plane magnetic field is parallel and perpendicular to the current. Surprisingly, both symmetric and antisymmetric components with respect to magnetic field are detected in the in-plane Hall resistivity. Further theoretical analysis suggests that the magnetotransport properties originate from the anomalous velocity induced by Berry curvature in a tilted Weyl semimetal. Our work not only enriches the Hall family but also provides new insights into the Berry phase effect in topological materials.
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Affiliation(s)
- Jun Ge
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Da Ma
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Yanzhao Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Huichao Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Yanan Li
- 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
| | - Tianchuang Luo
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Ying Xing
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Jiaqiang Yan
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - David Mandrus
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
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26
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Qin F, Li S, Du ZZ, Wang CM, Zhang W, Yu D, Lu HZ, Xie XC. Theory for the Charge-Density-Wave Mechanism of 3D Quantum Hall Effect. Phys Rev Lett 2020; 125:206601. [PMID: 33258643 DOI: 10.1103/physrevlett.125.206601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 09/23/2020] [Indexed: 06/12/2023]
Abstract
The charge-density-wave (CDW) mechanism of the 3D quantum Hall effect has been observed recently in ZrTe_{5} [Tang et al., Nature 569, 537 (2019)10.1038/s41586-019-1180-9]. Different from previous cases, the CDW forms on a one-dimensional (1D) band of Landau levels, which strongly depends on the magnetic field. However, its theory is still lacking. We develop a theory for the CDW mechanism of 3D quantum Hall effect. The theory can capture the main features in the experiments. We find a magnetic field induced second-order phase transition to the CDW phase. We find that electron-phonon interactions, rather than electron-electron interactions, dominate the order parameter. We extract the electron-phonon coupling constant from the non-Ohmic I-V relation. We point out a commensurate-incommensurate CDW crossover in the experiment. More importantly, our theory explores a rare case, in which a magnetic field can induce an order-parameter phase transition in one direction but a topological phase transition in other two directions, both depend on one magnetic field.
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Affiliation(s)
- Fang Qin
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026, China
- Shenzhen Municipal Key-Lab for Advanced Quantum Materials and Devices, Shenzhen 518055, China
| | - Shuai Li
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Z Z Du
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - C M Wang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- Department of Physics, Shanghai Normal University, Shanghai 200234, China
| | - Wenqing Zhang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Municipal Key-Lab for Advanced Quantum Materials and Devices, Shenzhen 518055, China
| | - Dapeng Yu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- 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, West Building 3, No. 10, Xibeiwang East Road, Haidian District, Beijing 100193, China
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27
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Wu X, Xiao D, Chen CZ, Sun J, Zhang L, Chan MHW, Samarth N, Xie XC, Lin X, Chang CZ. Scaling behavior of the quantum phase transition from a quantum-anomalous-Hall insulator to an axion insulator. Nat Commun 2020; 11:4532. [PMID: 32913228 PMCID: PMC7483742 DOI: 10.1038/s41467-020-18312-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 08/18/2020] [Indexed: 11/08/2022] Open
Abstract
The phase transitions from one plateau to the next plateau or to an insulator in quantum Hall and quantum anomalous Hall (QAH) systems have revealed universal scaling behaviors. A magnetic-field-driven quantum phase transition from a QAH insulator to an axion insulator was recently demonstrated in magnetic topological insulator sandwich samples. Here, we show that the temperature dependence of the derivative of the longitudinal resistance on magnetic field at the transition point follows a characteristic power-law that indicates a universal scaling behavior for the QAH to axion insulator phase transition. Similar to the quantum Hall plateau to plateau transition, the QAH to axion insulator transition can also be understood by the Chalker-Coddington network model. We extract a critical exponent κ ~ 0.38 ± 0.02 in agreement with recent high-precision numerical results on the correlation length exponent of the Chalker-Coddington model at ν ~ 2.6, rather than the generally-accepted value of 2.33.
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Affiliation(s)
- Xinyu Wu
- International Center for Quantum Materials, Peking University, Beijing, 100871, China
| | - Di Xiao
- Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Chui-Zhen Chen
- Institute for Advanced Study and School of Physical Science and Technology, Soochow University, Suzhou, 215006, China
| | - Jian Sun
- International Center for Quantum Materials, Peking University, Beijing, 100871, China
| | - Ling Zhang
- Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Moses H W Chan
- Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Nitin Samarth
- Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - X C Xie
- International Center for Quantum Materials, Peking University, Beijing, 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Xi Lin
- International Center for Quantum Materials, Peking University, Beijing, 100871, China.
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China.
| | - Cui-Zu Chang
- Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA.
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28
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Li H, Liu H, Jiang H, Xie XC. 3D Quantum Hall Effect and a Global Picture of Edge States in Weyl Semimetals. Phys Rev Lett 2020; 125:036602. [PMID: 32745387 DOI: 10.1103/physrevlett.125.036602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/08/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
We investigate the 3D quantum Hall effect in Weyl semimetals and elucidate a global picture of the edge states. The edge states hosting 3D quantum Hall effect are combinations of Fermi arcs and chiral Landau bands dispersing along the magnetic field direction. The Hall conductance, σ_{xz}^{H} [see Fig. 4], shows quantized plateaus with the variance of the magnetic field when the Fermi level is at the Weyl node. However, the chiral Landau bands can change the spatial distribution of the edge states, especially under a tilted magnetic field, and the resulting edge states lead to distinctive Hall transport phenomena. A tilted magnetic field contributes an intrinsic value to σ_{xz}^{H} and such an intrinsic value is determined by the tilting angle θ between the magnetic field and the y axis [see Fig. 1(c)]. Particularly, even if the perpendicular magnetic field is fixed, σ_{xz}^{H} will change its sign with an abrupt spatial shift of the edge states when θ exceeds a critical angle θ_{c}. Our work uncovers the novel edge-state nature of the 3D quantum Hall effect in Weyl semimetals.
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Affiliation(s)
- Hailong Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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29
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Wu Y, Jiang H, Liu J, Liu H, Xie XC. Non-Abelian Braiding of Dirac Fermionic Modes Using Topological Corner States in Higher-Order Topological Insulator. Phys Rev Lett 2020; 125:036801. [PMID: 32745393 DOI: 10.1103/physrevlett.125.036801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/13/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
We numerically demonstrate that the topological corner states residing in the corners of higher-order topological insulator possess non-Abelian braiding properties. Such topological corner states are Dirac fermionic modes other than Majorana zero modes. We claim that Dirac fermionic modes protected by nontrivial topology also support non-Abelian braiding. An analytical description on such non-Abelian braiding is conducted based on the vortex-induced Dirac-type fermionic modes. Finally, the braiding operators for Dirac fermionic modes, especially their explicit matrix forms, are analytically derived and compared with the case of Majorana zero modes.
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Affiliation(s)
- Yijia Wu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - Jie Liu
- Department of Applied Physics, School of Science, Xian Jiaotong University, Xian 710049, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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30
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Yang Y, Jia Z, Wu Y, Xiao RC, Hang ZH, Jiang H, Xie XC. Gapped topological kink states and topological corner states in honeycomb lattice. Sci Bull (Beijing) 2020; 65:531-537. [PMID: 36659184 DOI: 10.1016/j.scib.2020.01.024] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 12/30/2019] [Accepted: 01/15/2020] [Indexed: 01/21/2023]
Abstract
Based on the tight-binding calculations on honeycomb lattice and photonic experimental visualization on artificial graphene (AG), we report the domain-wall-induced gapped topological kink states and topological corner states. In honeycomb lattice, domain walls (DWs) with gapless topological kink states could be induced either by sublattice symmetry breaking or by lattice deformation. We find that the coexistence of these two mechanisms will induce DWs with gapped topological kink states. Significantly, the intersection of these two types of DWs gives rise to topological corner state localized at the crossing point. Through the manipulation of the DWs, we show AG with honeycomb lattice structure not only a versatile platform supporting multiple topological corner modes in a controlled manner, but also possessing promising applications such as fabricating topological quantum dots composed of gapped topological kink states and topological corner states.
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Affiliation(s)
- Yuting Yang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Ziyuan Jia
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Yijia Wu
- International Center for Quantum Materials, Peking University, Beijing 100871, China
| | - Rui-Chun Xiao
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Zhi Hong Hang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China; Institute for Advanced Study, Soochow University, Suzhou 215006, China.
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China; Institute for Advanced Study, Soochow University, Suzhou 215006, China.
| | - X C Xie
- International Center for Quantum Materials, Peking University, Beijing 100871, China; Beijing Academy of Quantum Information Sciences, Beijing 100193, China; CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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31
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Wu Y, Liu H, Liu J, Jiang H, Xie XC. Double-frequency Aharonov-Bohm effect and non-Abelian braiding properties of Jackiw-Rebbi zero-mode. Natl Sci Rev 2020; 7:572-578. [PMID: 34692076 PMCID: PMC8288965 DOI: 10.1093/nsr/nwz189] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/21/2019] [Accepted: 10/21/2019] [Indexed: 11/14/2022] Open
Abstract
Ever since its first proposal in 1976, Jackiw-Rebbi zero-mode has been drawing extensive attention for its charming properties including charge fractionalization, topologically protected zero-energy and possible non-Abelian statistics. We investigate these properties through the Jackiw-Rebbi zero-modes in quantum spin Hall insulators. Though charge fractionalization is not manifested, Jackiw-Rebbi zero-mode's zero-energy nature leads to a double-frequency Aharonov-Bohm effect, implying that it can be viewed as a special case of Majorana zero-mode without particle-hole symmetry. Such relation is strengthened for Jackiw-Rebbi zero-modes also exhibiting non-Abelian properties in the absence of superconductivity. Furthermore, in the condition that the degeneracy of Jackiw-Rebbi zero-modes is lifted, we demonstrate a novel non-Abelian braiding with continuously tunable fusion rule, which is a generalization of Majorana zero-modes' braiding properties.
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Affiliation(s)
- Yijia Wu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Jie Liu
- Department of Applied Physics, School of Science, Xi'an Jiaotong University, Xi'an 710049, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Beijing Academy of Quantum Information Sciences, Beijing 100193, China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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32
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Fu H, Wu Y, Zhang R, Sun J, Shan P, Wang P, Zhu Z, Pfeiffer LN, West KW, Liu H, Xie XC, Lin X. 3/2 fractional quantum Hall plateau in confined two-dimensional electron gas. Nat Commun 2019; 10:4351. [PMID: 31554799 PMCID: PMC6761136 DOI: 10.1038/s41467-019-12245-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 08/27/2019] [Indexed: 11/09/2022] Open
Abstract
Even-denominator fractional quantum Hall (FQH) states, such as 5/2 and 7/2, have been well known in a two-dimensional electron gas (2DEG) for decades and are still investigated as candidates of non-Abelian statistics. In this paper, we present the observation of a 3/2 FQH plateau in a single-layer 2DEG with lateral confinement at a bulk filling factor of 5/3. The 3/2 FQH plateau is quantized at \documentclass[12pt]{minimal}
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\begin{document}$$\left( {\frac{h}{{e^2}}} \right)/\left( {\frac{3}{2}} \right)$$\end{document}he2∕32 within 0.02%, and can survive up to 300 mK. This even-denominator FQH plateau may imply intriguing edge structure and excitation in FQH system with lateral confinement. The observations in this work demonstrate that understanding the effect of the lateral confinement on the many-body system is critical in the pursuit of important theoretical proposals involving edge physics, such as the demonstration of non-Abelian statistics and the realization of braiding for fault-tolerant quantum computation. Fractional quantum Hall states in 2D electron gases arise due to strong electron-electron interactions, which makes a general theoretical understanding difficult. Fu et al. present data showing the ν = 5/3 quantum Hall state has a 3/2 plateau in the diagonal resistance that has not been captured by existing models.
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Affiliation(s)
- Hailong Fu
- International Center for Quantum Materials, Peking University, 100871, Beijing, China.,Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Yijia Wu
- International Center for Quantum Materials, Peking University, 100871, Beijing, China
| | - Ruoxi Zhang
- International Center for Quantum Materials, Peking University, 100871, Beijing, China
| | - Jian Sun
- International Center for Quantum Materials, Peking University, 100871, Beijing, China
| | - Pujia Shan
- International Center for Quantum Materials, Peking University, 100871, Beijing, China
| | - Pengjie Wang
- International Center for Quantum Materials, Peking University, 100871, Beijing, China
| | - Zheyi Zhu
- International Center for Quantum Materials, Peking University, 100871, Beijing, China
| | - L N Pfeiffer
- Department of Electrical Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - K W West
- Department of Electrical Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, 100875, Beijing, China
| | - X C Xie
- International Center for Quantum Materials, Peking University, 100871, Beijing, China.,Beijing Academy of Quantum Information Sciences, 100193, Beijing, China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Xi Lin
- International Center for Quantum Materials, Peking University, 100871, Beijing, China. .,Beijing Academy of Quantum Information Sciences, 100193, Beijing, China. .,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, 100190, Beijing, China.
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33
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Abstract
The nonlinear Hall effect has opened the door towards deeper understanding of topological states of matter. Disorder plays indispensable roles in various linear Hall effects, such as the localization in the quantized Hall effects and the extrinsic mechanisms of the anomalous, spin, and valley Hall effects. Unlike in the linear Hall effects, disorder enters the nonlinear Hall effect even in the leading order. Here, we derive the formulas of the nonlinear Hall conductivity in the presence of disorder scattering. We apply the formulas to calculate the nonlinear Hall response of the tilted 2D Dirac model, which is the symmetry-allowed minimal model for the nonlinear Hall effect and can serve as a building block in realistic band structures. More importantly, we construct the general scaling law of the nonlinear Hall effect, which may help in experiments to distinguish disorder-induced contributions to the nonlinear Hall effect in the future.
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Affiliation(s)
- Z Z Du
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, China
- Peng Cheng Laboratory, Shenzhen, 518055, China
| | - C M Wang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, China
- Department of Physics, Shanghai Normal University, Shanghai, 200234, China
| | - Shuai Li
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China.
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, China.
- Peng Cheng Laboratory, Shenzhen, 518055, China.
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China
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34
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Cao Z, Zhang H, Lü HF, He WX, Lu HZ, Xie XC. Decays of Majorana or Andreev Oscillations Induced by Steplike Spin-Orbit Coupling. Phys Rev Lett 2019; 122:147701. [PMID: 31050472 DOI: 10.1103/physrevlett.122.147701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Indexed: 06/09/2023]
Abstract
The Majorana zero mode in the semiconductor-superconductor nanowire is one of the promising candidates for topological quantum computing. Recently, in islands of nanowires, subgap-state energies have been experimentally observed to oscillate as a function of the magnetic field, showing a signature of overlapped Majorana bound states. However, the oscillation amplitude either dies away after an overshoot or decays, sharply opposite to the theoretically predicted enhanced oscillations for Majorana bound states. We reveal that a steplike distribution of spin-orbit coupling in realistic devices can induce the decaying Majorana oscillations, resulting from the coupling-induced energy repulsion between the quasiparticle spectra on the two sides of the step. This steplike spin-orbit coupling can also lead to decaying oscillations in the spectrum of the Andreev bound states. For Coulomb-blockade peaks mediated by the Majorana bound states, the peak spacings have been predicted to correlate with peak heights by a π/2 phase shift, which was ambiguous in recent experiments and may be explained by the steplike spin-orbit coupling. Our work will inspire more works to reexamine effects of the nonuniform spin-orbit coupling, which is generally present in experimental devices.
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Affiliation(s)
- Zhan Cao
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- School of Physics, Southeast University, Nanjing 211189, China
- Peng Cheng Laboratory, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Hao Zhang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Hai-Feng Lü
- School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Wan-Xiu He
- Center for Interdisciplinary Studies and Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Peng Cheng Laboratory, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- 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
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35
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Chen CZ, Liu H, Xie XC. Effects of Random Domains on the Zero Hall Plateau in the Quantum Anomalous Hall Effect. Phys Rev Lett 2019; 122:026601. [PMID: 30720308 DOI: 10.1103/physrevlett.122.026601] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 11/10/2018] [Indexed: 06/09/2023]
Abstract
Recently, a zero Hall conductance plateau with random domains was experimentally observed in the quantum anomalous Hall (QAH) effect. We study the effects of random domains on the zero Hall plateau in QAH insulators. We find that the structure inversion symmetry determines the scaling property of the zero Hall plateau transition in the QAH systems. In the presence of structure inversion symmetry, the zero Hall plateau state shows a quantum-Hall-type critical point, originating from the two decoupled subsystems with opposite Chern numbers. However, the absence of structure inversion symmetry leads to a mixture between these two subsystems, gives rise to a line of critical points, and dramatically changes the scaling behavior. Hereinto, we predict a Berezinskii-Kosterlitz-Thouless-type transition during the Hall conductance plateau switching in the QAH insulators. Our results are instructive for both theoretic understanding of the zero Hall plateau transition and future transport experiments in the QAH insulators.
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Affiliation(s)
- Chui-Zhen Chen
- Institute for Advanced Study and School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - X C 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
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36
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Abstract
Unconventional responses upon breaking discrete or crystal symmetries open avenues for exploring emergent physical systems and materials. By breaking inversion symmetry, a nonlinear Hall signal can be observed, even in the presence of time-reversal symmetry, quite different from the conventional Hall effects. Low-symmetry two-dimensional materials are promising candidates for the nonlinear Hall effect, but it is less known when a strong nonlinear Hall signal can be measured, in particular, its connections with the band-structure properties. By using model analysis, we find prominent nonlinear Hall signals near tilted band anticrossings and band inversions. These band signatures can be used to explain the strong nonlinear Hall effect in the recent experiments on two-dimensional WTe_{2}. This Letter will be instructive not only for analyzing the transport signatures of the nonlinear Hall effect but also for exploring unconventional responses in emergent materials.
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Affiliation(s)
- Z Z Du
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- School of Physics, Southeast University, Nanjing 211189, China
| | - C M Wang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- Department of Physics, Shanghai Normal University, Shanghai 200234, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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37
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Wang H, Liu H, Li Y, Liu Y, Wang J, Liu J, Dai JY, Wang Y, Li L, Yan J, Mandrus D, Xie XC, Wang J. Discovery of log-periodic oscillations in ultraquantum topological materials. Sci Adv 2018; 4:eaau5096. [PMID: 30406205 PMCID: PMC6214643 DOI: 10.1126/sciadv.aau5096] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 09/25/2018] [Indexed: 05/30/2023]
Abstract
Quantum oscillations are usually the manifestation of the underlying physical nature in condensed matter systems. Here, we report a new type of log-periodic quantum oscillations in ultraquantum three-dimensional topological materials. Beyond the quantum limit (QL), we observe the log-periodic oscillations involving up to five oscillating cycles (five peaks and five dips) on the magnetoresistance of high-quality single-crystal ZrTe5, virtually showing the clearest feature of discrete scale invariance (DSI). Further, theoretical analyses show that the two-body quasi-bound states can be responsible for the DSI feature. Our work provides a new perspective on the ground state of topological materials beyond the QL.
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Affiliation(s)
- Huichao Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Yanan Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Yongjie Liu
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, 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
| | - Ji-Yan Dai
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, 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
| | - 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
| | - X. C. 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
| | - 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
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38
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Cheng SG, Liu H, Jiang H, Sun QF, Xie XC. Manipulation and Characterization of the Valley-Polarized Topological Kink States in Graphene-Based Interferometers. Phys Rev Lett 2018; 121:156801. [PMID: 30362779 DOI: 10.1103/physrevlett.121.156801] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Indexed: 06/08/2023]
Abstract
Valley polarized topological kink states, existing broadly in the domain wall of hexagonal lattice systems, are identified in experiments. Unfortunately, only very limited physical properties are given. Using an Aharanov-Bohm interferometer composed of domain walls in graphene systems, we study the periodical modulation of a pure valley current in a large range by tuning the magnetic field or the Fermi level. For a monolayer graphene device, there exists one topological kink state, and the oscillation of the transmission coefficients has a single period. The π Berry phase and the linear dispersion relation of kink states can be extracted from the transmission data. For a bilayer graphene device, there are two topological kink states with two oscillation periods. Our proposal provides an experimentally feasible route to manipulate and characterize the valley-polarized topological kink states in classical wave and electronic graphene-type crystalline systems.
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Affiliation(s)
- Shu-Guang Cheng
- Department of Physics, Northwest University, Xi'an 710069, China
- Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi'an 710069, China
| | - Haiwen Liu
- Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Hua Jiang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Institute for Advanced Study, Soochow University, Suzhou 215006, China
| | - Qing-Feng Sun
- 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
| | - X C 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
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39
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Chen Y, Lu HZ, Xie XC. Forbidden Backscattering and Resistance Dip in the Quantum Limit as a Signature for Topological Insulators. Phys Rev Lett 2018; 121:036602. [PMID: 30085828 DOI: 10.1103/physrevlett.121.036602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/02/2018] [Indexed: 06/08/2023]
Abstract
Identifying topological insulators and semimetals often focuses on their surface states, using spectroscopic methods such as angle-resolved photoemission spectroscopy or scanning tunneling microscopy. In contrast, studying the topological properties of topological insulators from their bulk-state transport is more accessible in most labs but seldom addressed. We show that, in the quantum limit of a topological insulator, the backscattering between the only two states on the Fermi surface of the lowest Landau band can be forbidden at a critical magnetic field. The conductivity is determined solely by the backscattering between the two states, leading to a resistance dip that may serve as a signature for topological insulator phases. More importantly, this forbidden backscattering mechanism for the resistance dip is irrelevant to details of disorder scattering. Our theory can be applied to revisit the experiments on Pb_{1-x}Sn_{x}Se, ZrTe_{5}, and Ag_{2}Te families, and will be particularly useful for controversial small-gap materials at the boundary between topological and normal insulators.
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Affiliation(s)
- Yiyuan Chen
- Shenzhen Institute for Quantum Science and Technology and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Technology and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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40
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Li C, Wang CM, Wan B, Wan X, Lu HZ, Xie XC. Rules for Phase Shifts of Quantum Oscillations in Topological Nodal-Line Semimetals. Phys Rev Lett 2018; 120:146602. [PMID: 29694159 DOI: 10.1103/physrevlett.120.146602] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/01/2018] [Indexed: 05/12/2023]
Abstract
Nodal-line semimetals are topological semimetals in which band touchings form nodal lines or rings. Around a loop that encloses a nodal line, an electron can accumulate a nontrivial π Berry phase, so the phase shift in the Shubnikov-de Haas (SdH) oscillation may give a transport signature for the nodal-line semimetals. However, different experiments have reported contradictory phase shifts, in particular, in the WHM nodal-line semimetals (W=Zr/Hf, H=Si/Ge, M=S/Se/Te). For a generic model of nodal-line semimetals, we present a systematic calculation for the SdH oscillation of resistivity under a magnetic field normal to the nodal-line plane. From the analytical result of the resistivity, we extract general rules to determine the phase shifts for arbitrary cases and apply them to ZrSiS and Cu_{3}PdN systems. Depending on the magnetic field directions, carrier types, and cross sections of the Fermi surface, the phase shift shows rich results, quite different from those for normal electrons and Weyl fermions. Our results may help explore transport signatures of topological nodal-line semimetals and can be generalized to other topological phases of matter.
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Affiliation(s)
- Cequn Li
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - C M Wang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
- School of Physics and Electrical Engineering, Anyang Normal University, Anyang 455000, China
| | - Bo Wan
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing 210093, China
| | - Xiangang Wan
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing 210093, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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41
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Yuan W, Zhu Q, Su T, Yao Y, Xing W, Chen Y, Ma Y, Lin X, Shi J, Shindou R, Xie XC, Han W. Experimental signatures of spin superfluid ground state in canted antiferromagnet Cr 2O 3 via nonlocal spin transport. Sci Adv 2018; 4:eaat1098. [PMID: 29662956 PMCID: PMC5898847 DOI: 10.1126/sciadv.aat1098] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 02/22/2018] [Indexed: 05/26/2023]
Abstract
Spin superfluid is a novel emerging quantum matter arising from the Bose-Einstein condensate (BEC) of spin-1 bosons. We demonstrate the spin superfluid ground state in canted antiferromagnetic Cr2O3 thin film at low temperatures via nonlocal spin transport. A large enhancement of the nonlocal spin signal is observed below ~20 K, and it saturates from ~5 down to 2 K. We show that the spins can propagate over very long distances (~20 μm) in such spin superfluid ground state and that the nonlocal spin signal decreases very slowly as the spacing increases with an inverse relationship, which is consistent with theoretical prediction. Furthermore, spin superfluidity has been investigated in the canted antiferromagnetic phase of the (11[Formula: see text]0)-oriented Cr2O3 film, where the magnetic field dependence of the associated critical temperature follows a 2/3 power law near the critical point. The experimental demonstration of the spin superfluid ground state in canted antiferromagnet will be extremely important for the fundamental physics on the BEC of spin-1 bosons and paves the way for future spin supercurrent devices, such as spin-Josephson junctions.
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Affiliation(s)
- Wei Yuan
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Qiong Zhu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Tang Su
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Yunyan Yao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Wenyu Xing
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Yangyang Chen
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Yang Ma
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Xi Lin
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Jing Shi
- Department of Physics and Astronomy, University of California, Riverside, Riverside, CA 92521, USA
| | - Ryuichi Shindou
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - X. C. Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
| | - Wei Han
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China
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42
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Chen Y, Xing W, Wang X, Shen B, Yuan W, Su T, Ma Y, Yao Y, Zhong J, Yun Y, Xie XC, Jia S, Han W. Role of Oxygen in Ionic Liquid Gating on Two-Dimensional Cr 2Ge 2Te 6: A Non-oxide Material. ACS Appl Mater Interfaces 2018; 10:1383-1388. [PMID: 29251913 DOI: 10.1021/acsami.7b14795] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ionic liquid gating can markedly modulate a material's carrier density so as to induce metallization, superconductivity, and quantum phase transitions. One of the main issues is whether the mechanism of ionic liquid gating is an electrostatic field effect or an electrochemical effect, especially for oxide materials. Recent observation of the suppression of the ionic liquid gate-induced metallization in the presence of oxygen for oxide materials suggests the electrochemical effect. However, in more general scenarios, the role of oxygen in the ionic liquid gating effect is still unclear. Here, we perform ionic liquid gating experiments on a non-oxide material: two-dimensional ferromagnetic Cr2Ge2Te6. Our results demonstrate that despite the large increase of the gate leakage current in the presence of oxygen, the oxygen does not affect the ionic liquid gating effect on the channel resistance of Cr2Ge2Te6 devices (<5% difference), which suggests the electrostatic field effect as the mechanism on non-oxide materials. Moreover, our results show that ionic liquid gating is more effective on the modulation of the channel resistances compared to the back gating across the 300 nm thick SiO2.
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Affiliation(s)
- Yangyang Chen
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Wenyu Xing
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Xirui Wang
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Bowen Shen
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Wei Yuan
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Tang Su
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Yang Ma
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Yunyan Yao
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Jiangnan Zhong
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Yu Yun
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Shuang Jia
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Wei Han
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
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Abstract
The quantum Hall effect is usually observed in 2D systems. We show that the Fermi arcs can give rise to a distinctive 3D quantum Hall effect in topological semimetals. Because of the topological constraint, the Fermi arc at a single surface has an open Fermi surface, which cannot host the quantum Hall effect. Via a "wormhole" tunneling assisted by the Weyl nodes, the Fermi arcs at opposite surfaces can form a complete Fermi loop and support the quantum Hall effect. The edge states of the Fermi arcs show a unique 3D distribution, giving an example of (d-2)-dimensional boundary states. This is distinctly different from the surface-state quantum Hall effect from a single surface of topological insulator. As the Fermi energy sweeps through the Weyl nodes, the sheet Hall conductivity evolves from the 1/B dependence to quantized plateaus at the Weyl nodes. This behavior can be realized by tuning gate voltages in a slab of topological semimetal, such as the TaAs family, Cd_{3}As_{2}, or Na_{3}Bi. This work will be instructive not only for searching transport signatures of the Fermi arcs but also for exploring novel electron gases in other topological phases of matter.
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Affiliation(s)
- C M Wang
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China, Shenzhen 518055, China
- School of Physics and Electrical Engineering, Anyang Normal University, Anyang 455000, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Hai-Peng Sun
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Hai-Zhou Lu
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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44
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Xie XC, Wang L, Jia TT, Ma DY. [Acute suppurative otitis media caused by pasteurella multocida :a case report]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2017; 31:153-154. [PMID: 29871210 DOI: 10.13201/j.issn.1001-1781.2017.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Indexed: 11/12/2022]
Abstract
The pasteurella multocida (PM) is widely gastrointestinal parasitic on dogs, cats and other animals. The PM human infections is caused by animal bites orits close contact. Clinically foundin focal wound infection after bite, and acute suppurative otitis media reportshave not been caused by PM. A 45 years old nasopharyngeal cancer who sudden stabbing painof the left ear for 5h. Physical examination found that the left earexisted a lot of yellowish white purulent secretion. Distribution and drug sensitivity test of bacteria showed PM and it was sensitive to many antibiotics. nasopharygo fiberscope revealed that eustachian tube and theleft ear had a large number of purulentsecretion. The main diagnosis was: ①Recurrent nasopharyngealcarcinoma; ② Acute suppurative otitis media. TREATMENT according to the results of drug sensitive test and skin test inpatients with selection of levofloxacin (0.2 g/12 h), clindamycin (0.6 g/12 h) anti-infection treatment, the patient get better in the end.
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45
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Song Q, Mi J, Zhao D, Su T, Yuan W, Xing W, Chen Y, Wang T, Wu T, Chen XH, Xie XC, Zhang C, Shi J, Han W. Spin injection and inverse Edelstein effect in the surface states of topological Kondo insulator SmB 6. Nat Commun 2016; 7:13485. [PMID: 27834378 PMCID: PMC5114616 DOI: 10.1038/ncomms13485] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 10/03/2016] [Indexed: 11/09/2022] Open
Abstract
There has been considerable interest in exploiting the spin degrees of freedom of electrons for potential information storage and computing technologies. Topological insulators (TIs), a class of quantum materials, have special gapless edge/surface states, where the spin polarization of the Dirac fermions is locked to the momentum direction. This spin-momentum locking property gives rise to very interesting spin-dependent physical phenomena such as the Edelstein and inverse Edelstein effects. However, the spin injection in pure surface states of TI is very challenging because of the coexistence of the highly conducting bulk states. Here, we experimentally demonstrate the spin injection and observe the inverse Edelstein effect in the surface states of a topological Kondo insulator, SmB6. At low temperatures when only surface carriers are present, a clear spin signal is observed. Furthermore, the magnetic field angle dependence of the spin signal is consistent with spin-momentum locking property of surface states of SmB6.
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Affiliation(s)
- Qi Song
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Jian Mi
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Dan Zhao
- Hefei National Laboratory for Physical Science at Microscale, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China
| | - Tang Su
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Wei Yuan
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Wenyu Xing
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Yangyang Chen
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Tianyu Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Tao Wu
- Hefei National Laboratory for Physical Science at Microscale, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China.,Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xian Hui Chen
- Hefei National Laboratory for Physical Science at Microscale, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China.,Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.,High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Chi Zhang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Jing Shi
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Wei Han
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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46
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Chen H, Liu XJ, Xie XC. Chern Kondo Insulator in an Optical Lattice. Phys Rev Lett 2016; 116:046401. [PMID: 26871345 DOI: 10.1103/physrevlett.116.046401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Indexed: 06/05/2023]
Abstract
We propose to realize and observe Chern Kondo insulators in an optical superlattice with laser-assisted s and p orbital hybridization and a synthetic gauge field, which can be engineered based on the recent cold atom experiments. Considering a double-well square optical lattice, the localized s orbitals are decoupled from itinerant p bands and are driven into a Mott insulator due to the strong Hubbard interaction. Raman laser beams are then applied to induce tunnelings between s and p orbitals, and generate a staggered flux simultaneously. Because of the strong Hubbard interaction of s orbital states, we predict the existence of a critical Raman laser-assisted coupling, beyond which the Kondo screening is achieved, and then a fully gapped Chern Kondo phase emerges, with the topology characterized by integer Chern numbers. Being a strongly correlated topological state, the Chern Kondo phase is different from the single-particle quantum anomalous Hall state, and can be identified by measuring the band topology and double occupancy of s orbitals. The experimental realization and detection of the predicted Chern Kondo insulator are also proposed.
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Affiliation(s)
- Hua Chen
- International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Xiong-Jun Liu
- International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - X C Xie
- International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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47
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Wang H, Wang H, Liu H, Lu H, Yang W, Jia S, Liu XJ, Xie XC, Wei J, Wang J. Observation of superconductivity induced by a point contact on 3D Dirac semimetal Cd3As2 crystals. Nat Mater 2016; 15:38-42. [PMID: 26524129 DOI: 10.1038/nmat4456] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 09/17/2015] [Indexed: 06/05/2023]
Abstract
Three-dimensional (3D) Dirac semimetals, which possess 3D linear dispersion in the electronic structure as a bulk analogue of graphene, have lately generated widespread interest in both materials science and condensed matter physics. Recently, crystalline Cd3As2 has been proposed and proved to be a 3D Dirac semimetal that can survive in the atmosphere. Here, by using point contact spectroscopy measurements, we observe exotic superconductivity around the point contact region on the surface of Cd3As2 crystals. The zero-bias conductance peak (ZBCP) and double conductance peaks (DCPs) symmetric around zero bias suggest p-wave-like unconventional superconductivity. Considering the topological properties of 3D Dirac semimetals, our findings may indicate that Cd3As2 crystals under certain conditions could be topological superconductors, which are predicted to support Majorana zero modes or gapless Majorana edge/surface modes in the boundary depending on the dimensionality of the material.
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Affiliation(s)
- He Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Huichao Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Haiwen Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Hong Lu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Wuhao Yang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Shuang Jia
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Xiong-Jun Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Jian Wei
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, 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
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48
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Chen CZ, Song J, Jiang H, Sun QF, Wang Z, Xie XC. Disorder and Metal-Insulator Transitions in Weyl Semimetals. Phys Rev Lett 2015; 115:246603. [PMID: 26705648 DOI: 10.1103/physrevlett.115.246603] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Indexed: 06/05/2023]
Abstract
The Weyl semimetal (WSM) is a newly proposed quantum state of matter. It has Weyl nodes in bulk excitations and Fermi arc surface states. We study the effects of disorder and localization in WSMs and find three novel phase transitions. (i) Two Weyl nodes near the Brillouin zone boundary can be annihilated pairwise by disorder scattering, resulting in the opening of a topologically nontrivial gap and a transition from a WSM to a three-dimensional quantum anomalous Hall state. (ii) When the two Weyl nodes are well separated in momentum space, the emergent bulk extended states can give rise to a direct transition from a WSM to a 3D diffusive anomalous Hall metal. (iii) Two Weyl nodes can emerge near the zone center when an insulating gap closes with increasing disorder, enabling a direct transition from a normal band insulator to a WSM. We determine the phase diagram by numerically computing the localization length and the Hall conductivity, and propose that the novel phase transitions can be realized on a photonic lattice.
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Affiliation(s)
- Chui-Zhen Chen
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Juntao Song
- Department of Physics, Hebei Normal University, Hebei 050024, China
| | - Hua Jiang
- College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, China
| | - Qing-feng Sun
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02167, USA
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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49
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Xing Y, Zhang HM, Fu HL, Liu H, Sun Y, Peng JP, Wang F, Lin X, Ma XC, Xue QK, Wang J, Xie XC. Quantum Griffiths singularity of superconductor-metal transition in Ga thin films. Science 2015; 350:542-5. [DOI: 10.1126/science.aaa7154] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 09/21/2015] [Indexed: 11/02/2022]
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50
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Abstract
The Goos-Hänchen (GH) shift and the Imbert-Fedorov (IF) shift are optical phenomena which describe the longitudinal and transverse lateral shifts at the reflection interface, respectively. Here, we predict the GH and IF shifts in Weyl semimetals (WSMs)-a promising material harboring low energy Weyl fermions, a massless fermionic cousin of photons. Our results show that the GH shift in WSMs is valley independent, which is analogous to that discovered in a 2D relativistic material-graphene. However, the IF shift has never been explored in nonoptical systems, and here we show that it is valley dependent. Furthermore, we find that the IF shift actually originates from the topological effect of the system. Experimentally, the topological IF shift can be utilized to characterize the Weyl semimetals, design valleytronic devices of high efficiency, and measure the Berry curvature.
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Affiliation(s)
- Qing-Dong Jiang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Hua Jiang
- College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, People's Republic of China
| | - Haiwen Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China
| | - Qing-Feng Sun
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China
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