1
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Li Y, Wang Y, Lian Z, Li H, Gao Z, Xu L, Wang H, Lu R, Li L, Feng Y, Zhu J, Liu L, Wang Y, Fu B, Yang S, Yang L, Wang Y, Xia T, Liu C, Jia S, Wu Y, Zhang J, Wang Y, Liu C. Fabrication-induced even-odd discrepancy of magnetotransport in few-layer MnBi 2Te 4. Nat Commun 2024; 15:3399. [PMID: 38649376 PMCID: PMC11035656 DOI: 10.1038/s41467-024-47779-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 04/12/2024] [Indexed: 04/25/2024] Open
Abstract
The van der Waals antiferromagnetic topological insulator MnBi2Te4 represents a promising platform for exploring the layer-dependent magnetism and topological states of matter. Recently observed discrepancies between magnetic and transport properties have aroused controversies concerning the topological nature of MnBi2Te4 in the ground state. In this article, we demonstrate that fabrication can induce mismatched even-odd layer dependent magnetotransport in few-layer MnBi2Te4. We perform a comprehensive study of the magnetotransport properties in 6- and 7-septuple-layer MnBi2Te4, and reveal that both even- and odd-number-layer device can show zero Hall plateau phenomena in zero magnetic field. Importantly, a statistical survey of the optical contrast in more than 200 MnBi2Te4 flakes reveals that the zero Hall plateau in odd-number-layer devices arises from the reduction of the effective thickness during the fabrication, a factor that was rarely noticed in previous studies of 2D materials. Our finding not only provides an explanation to the controversies regarding the discrepancy of the even-odd layer dependent magnetotransport in MnBi2Te4, but also highlights the critical issues concerning the fabrication and characterization of 2D material devices.
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Affiliation(s)
- Yaoxin Li
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, China
| | - Yongchao Wang
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, China
| | - Zichen Lian
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, China
| | - Hao Li
- School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
- Department of Physics, Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing, 100084, China
| | - Zhiting Gao
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
| | - Liangcai Xu
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, China
| | - Huan Wang
- Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872, Beijing, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Rui'e Lu
- School of Mechanical and Electric Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Longfei Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Yang Feng
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
| | - Jinjiang Zhu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
| | - Liangyang Liu
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, China
| | - Yongqian Wang
- Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872, Beijing, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Bohan Fu
- Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872, Beijing, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Shuai Yang
- Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872, Beijing, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Luyi Yang
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, China
- Frontier Science Center for Quantum Information, Beijing, 100084, China
| | - Yihua Wang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, 200433, China
- Shanghai Research Center for Quantum Sciences, Shanghai, 201315, China
| | - Tianlong Xia
- Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872, Beijing, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Chang Liu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Shuang Jia
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing, 100871, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Yang Wu
- College of Math and Physics, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Jinsong Zhang
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, China
- Frontier Science Center for Quantum Information, Beijing, 100084, China
- Hefei National Laboratory, Hefei, 230088, China
| | - Yayu Wang
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing, 100084, China
- Frontier Science Center for Quantum Information, Beijing, 100084, China
- Hefei National Laboratory, Hefei, 230088, China
| | - Chang Liu
- Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872, Beijing, China.
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China.
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Mei R, Zhao YF, Wang C, Ren Y, Xiao D, Chang CZ, Liu CX. Electrically Controlled Anomalous Hall Effect and Orbital Magnetization in Topological Magnet MnBi_{2}Te_{4}. PHYSICAL REVIEW LETTERS 2024; 132:066604. [PMID: 38394580 DOI: 10.1103/physrevlett.132.066604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 12/22/2023] [Indexed: 02/25/2024]
Abstract
We propose an intrinsic mechanism to understand the even-odd effect, namely, opposite signs of anomalous Hall resistance and different shapes of hysteresis loops for even and odd septuple layers (SLs), of MBE-grown MnBi_{2}Te_{4} thin films with electron doping. The nonzero hysteresis loops in the anomalous Hall effect and magnetic circular dichroism for even-SLs MnBi_{2}Te_{4} films originate from two different antiferromagnetic (AFM) configurations with different zeroth Landau level energies of surface states. The complex form of the anomalous Hall hysteresis loop can be understood from two magnetic transitions, a transition between two AFM states followed by a second transition to the ferromagnetic state. Our model also clarifies the relationship and distinction between axion parameter and magnetoelectric coefficient, and shows an even-odd oscillation behavior of magnetoelectric coefficients in MnBi_{2}Te_{4} films.
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Affiliation(s)
- Ruobing Mei
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Yi-Fan Zhao
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Chong Wang
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Yafei Ren
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Di Xiao
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - Cui-Zu Chang
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Chao-Xing Liu
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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3
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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] [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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4
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Wang Y, Ma XM, Hao Z, Cai Y, Rong H, Zhang F, Chen W, Zhang C, Lin J, Zhao Y, Liu C, Liu Q, Chen C. On the topological surface states of the intrinsic magnetic topological insulator Mn-Bi-Te family. Natl Sci Rev 2024; 11:nwad066. [PMID: 38213518 PMCID: PMC10776371 DOI: 10.1093/nsr/nwad066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/12/2022] [Accepted: 01/03/2023] [Indexed: 01/13/2024] Open
Abstract
We review recent progress in the electronic structure study of intrinsic magnetic topological insulators (MnBi2Te4) · (Bi2Te3)n ([Formula: see text]) family. Specifically, we focus on the ubiquitously (nearly) gapless behavior of the topological Dirac surface state observed by photoemission spectroscopy, even though a large Dirac gap is expected because of surface ferromagnetic order. The dichotomy between experiment and theory concerning this gap behavior is perhaps the most critical and puzzling question in this frontier. We discuss various proposals accounting for the lack of magnetic effect on the topological Dirac surface state, which are mainly categorized into two pictures, magnetic reconfiguration and topological surface state redistribution. Band engineering towards opening a magnetic gap of topological surface states provides great opportunities to realize quantized topological transport and axion electrodynamics at higher temperatures.
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Affiliation(s)
- Yuan Wang
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Xiao-Ming Ma
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Zhanyang Hao
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Yongqing Cai
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Hongtao Rong
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Fayuan Zhang
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Weizhao Chen
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Chengcheng Zhang
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Junhao Lin
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Yue Zhao
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Chang Liu
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Qihang Liu
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Chaoyu Chen
- Shenzhen Institute for Quantum Science and Engineering (SIQSE) and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
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5
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Xu R, Xu L, Liu Z, Yang L, Chen Y. ARPES investigation of the electronic structure and its evolution in magnetic topological insulator MnBi 2+2nTe 4+3n family. Natl Sci Rev 2024; 11:nwad313. [PMID: 38327664 PMCID: PMC10849349 DOI: 10.1093/nsr/nwad313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/14/2023] [Accepted: 11/19/2023] [Indexed: 02/09/2024] Open
Abstract
In the past 5 years, there has been significant research interest in the intrinsic magnetic topological insulator family compounds MnBi2+2nTe4+3n (where n = 0, 1, 2 …). In particular, exfoliated thin films of MnBi2Te4 have led to numerous experimental breakthroughs, such as the quantum anomalous Hall effect, axion insulator phase and high-Chern number quantum Hall effect without Landau levels. However, despite extensive efforts, the energy gap of the topological surface states due to exchange magnetic coupling, which is a key feature of the characteristic band structure of the system, remains experimentally elusive. The electronic structure measured by using angle-resolved photoemission (ARPES) shows significant deviation from ab initio prediction and scanning tunneling spectroscopy measurements, making it challenging to understand the transport results based on the electronic structure. This paper reviews the measurements of the band structure of MnBi2+2nTe4+3n magnetic topological insulators using ARPES, focusing on the evolution of their electronic structures with temperature, surface and bulk doping and film thickness. The aim of the review is to construct a unified picture of the electronic structure of MnBi2+2nTe4+3n compounds and explore possible control of their topological properties.
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Affiliation(s)
- Runzhe Xu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Lixuan Xu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai 201210, China
| | - Zhongkai Liu
- School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Lexian Yang
- 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
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Yulin Chen
- School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
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6
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Ahn J, Kang SH, Yoon M, Ganesh P, Krogel JT. Stacking Faults and Topological Properties in MnBi 2Te 4: Reconciling Gapped and Gapless States. J Phys Chem Lett 2023; 14:9052-9059. [PMID: 37782759 DOI: 10.1021/acs.jpclett.3c01939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Despite theoretical predictions of a gapped surface state for the magnetic topological insulator MnBi2Te4 (MBT), there has been a series of experimental evidence pointing toward gapless states. Here, we theoretically explore how stacking faults could influence the topological characteristics of MBT. We envisage a scenario that a stacking fault exists at the surface of MBT, causing the uppermost layer to deviate from the ground state and its interlayer separation to be expanded. This stacking fault with modulated interlayer couplings hosts a nearly gapless state within the topmost layer due to charge redistribution as the outermost layer recedes. Furthermore, we find evidence of spin-momentum locking and preservation of weak band inversion in the gapless surface state, suggesting the nontrivial topological surface states in the presence of the stacking fault. Our findings provide a plausible elucidation to the long-standing conundrum of reconciling the observation of gapped and gapless states on MBT surfaces.
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Affiliation(s)
- Jeonghwan Ahn
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Seoung-Hun Kang
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Mina Yoon
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Panchapakesan Ganesh
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jaron T Krogel
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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7
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Volckaert K, Majchrzak P, Biswas D, Jones AJH, Bianchi M, Jiang Z, Dubourg R, Stenshøj RØ, Jensen ML, Jones NC, Hoffmann SV, Mi JL, Bremholm M, Pan XC, Chen YP, Hofmann P, Miwa JA, Ulstrup S. Surface Electronic Structure Engineering of Manganese Bismuth Tellurides Guided by Micro-Focused Angle-Resolved Photoemission. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301907. [PMID: 37204117 DOI: 10.1002/adma.202301907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/08/2023] [Indexed: 05/20/2023]
Abstract
Modification of the electronic structure of quantum matter by ad atom deposition allows for directed fundamental design of electronic and magnetic properties. This concept is utilized in the present study in order to tune the surface electronic structure of magnetic topological insulators based on MnBi2 Te4 . The topological bands of these systems are typically strongly electron-doped and hybridized with a manifold of surface states that place the salient topological states out of reach of electron transport and practical applications. In this study, micro-focused angle-resolved photoemission spectroscopy (microARPES) provides direct access to the termination-dependent dispersion of MnBi2 Te4 and MnBi4 Te7 during in situ deposition of rubidium atoms. The resulting band structure changes are found to be highly complex, encompassing coverage-dependent ambipolar doping effects, removal of surface state hybridization, and the collapse of a surface state band gap. In addition, doping-dependent band bending is found to give rise to tunable quantum well states. This wide range of observed electronic structure modifications can provide new ways to exploit the topological states and the rich surface electronic structures of manganese bismuth tellurides.
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Affiliation(s)
- Klara Volckaert
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Paulina Majchrzak
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Deepnarayan Biswas
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Alfred J H Jones
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Marco Bianchi
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Zhihao Jiang
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Raphaël Dubourg
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Rasmus Ørnekoll Stenshøj
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Mads Lykke Jensen
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Nykola C Jones
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Søren V Hoffmann
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Jian-Li Mi
- Department of Chemistry, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Martin Bremholm
- Department of Chemistry, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Xing-Chen Pan
- Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - Yong P Chen
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
- Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
- Department of Physics and Astronomy and School of Electrical and Computer Engineering and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, IN, 47907, USA
| | - Philip Hofmann
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Jill A Miwa
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
| | - Søren Ulstrup
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, 8000, Denmark
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8
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Estyunina TP, Shikin AM, Estyunin DA, Eryzhenkov AV, Klimovskikh II, Bokai KA, Golyashov VA, Kokh KA, Tereshchenko OE, Kumar S, Shimada K, Tarasov AV. Evolution of Mn 1-xGe xBi 2Te 4 Electronic Structure under Variation of Ge Content. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2151. [PMID: 37513162 PMCID: PMC10384094 DOI: 10.3390/nano13142151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/22/2023] [Accepted: 07/23/2023] [Indexed: 07/30/2023]
Abstract
One of the approaches to manipulate MnBi2Te4 properties is the magnetic dilution, which inevitably affects the interplay of magnetism and band topology in the system. In this work, we carried out angle-resolved photoemission spectroscopy (ARPES) measurements and density functional theory (DFT) calculations for analysing changes in the electronic structure of Mn1-xGexBi2Te4 that occur under parameter x variation. We consider two ways of Mn/Ge substitution: (i) bulk doping of the whole system; (ii) surface doping of the first septuple layer. For the case (i), the experimental results reveal a decrease in the value of the bulk band gap, which should be reversed by an increase when the Ge concentration reaches a certain value. Ab-initio calculations show that at Ge concentrations above 50%, there is an absence of the bulk band inversion of the Te pz and Bi pz contributions at the Γ-point with significant spatial redistribution of the states at the band gap edges into the bulk, suggesting topological phase transition in the system. For case (ii) of the vertical heterostructure Mn1-xGexBi2Te4/MnBi2Te4, it was shown that an increase of Ge concentration in the first septuple layer leads to effective modulation of the Dirac gap in the absence of significant topological surface states of spatial redistribution. The results obtained indicate that surface doping compares favorably compared to bulk doping as a method for the Dirac gap value modulation.
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Affiliation(s)
- Tatiana P Estyunina
- Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
| | - Alexander M Shikin
- Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
| | - Dmitry A Estyunin
- Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
| | | | - Ilya I Klimovskikh
- Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
| | - Kirill A Bokai
- Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
| | - Vladimir A Golyashov
- Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
- Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Kol'tsovo 630559, Russia
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Konstantin A Kokh
- Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
- Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Oleg E Tereshchenko
- Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
- Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Kol'tsovo 630559, Russia
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Shiv Kumar
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan
| | - Kenya Shimada
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan
| | - Artem V Tarasov
- Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
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9
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Abstract
MnBi2Te4, an antiferromagnetic topological insulator, was theoretically predicted to have a gapped surface state on its (111) surface. However, a much smaller gapped or even gapless surface state has been observed experimentally, which is thought to be caused by the defects in MnBi2Te4. Here, we have theoretically identified the antisite MnBi and BiMn as dominant defects and revealed their evolution during the phase transition from MnTe/Bi2Te3 to MnBi2Te4. We found that the complete elimination of MnBi and BiMn defects in MnBi2Te4 by simple annealing is almost impossible due to the high migration barrier in kinetics. Moreover, the gap of the Dirac point-related bands in a MnBi2Te4 monolayer would be eliminated with an increasing concentration of MnBi and BiMn defects, which could explain the experimentally unobserved large-gap surface state in MnBi2Te4. Our results provide an insight into the theoretical understanding of the quality and the experimentally measured topological properties of the synthesized MnBi2Te4.
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Affiliation(s)
- Xi Wu
- Shenzhen Geim Graphene Center and Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, People's Republic of China
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Chao Ruan
- Shenzhen Geim Graphene Center and Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, People's Republic of China
| | - Peizhe Tang
- School of Materials Science and Engineering, Beihang University, Beijing 100191, People's Republic of China
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free Electron Laser Science, Hamburg 22761, Germany
| | - Feiyu Kang
- Shenzhen Geim Graphene Center and Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, People's Republic of China
| | - Wenhui Duan
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
- Institute for Advanced Study, Tsinghua University, Beijing 100084, People's Republic of China
- Frontier Science Center for Quantum Information, Beijing 100084, People's Republic of China
| | - Jia Li
- Shenzhen Geim Graphene Center and Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, People's Republic of China
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10
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Tan H, Yan B. Distinct Magnetic Gaps between Antiferromagnetic and Ferromagnetic Orders Driven by Surface Defects in the Topological Magnet MnBi_{2}Te_{4}. PHYSICAL REVIEW LETTERS 2023; 130:126702. [PMID: 37027867 DOI: 10.1103/physrevlett.130.126702] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 03/03/2023] [Indexed: 06/09/2023]
Abstract
Many experiments observed a metallic behavior at zero magnetic fields (antiferromagnetic phase, AFM) in MnBi_{2}Te_{4} thin film transport, which coincides with gapless surface states observed by angle-resolved photoemission spectroscopy, while it can become a Chern insulator at field larger than 6 T (ferromagnetic phase, FM). Thus, the zero-field surface magnetism was once speculated to be different from the bulk AFM phase. However, recent magnetic force microscopy refutes this assumption by detecting persistent AFM order on the surface. In this Letter, we propose a mechanism related to surface defects that can rationalize these contradicting observations in different experiments. We find that co-antisites (exchanging Mn and Bi atoms in the surface van der Waals layer) can strongly suppress the magnetic gap down to several meV in the AFM phase without violating the magnetic order but preserve the magnetic gap in the FM phase. The different gap sizes between AFM and FM phases are caused by the exchange interaction cancellation or collaboration of the top two van der Waals layers manifested by defect-induced surface charge redistribution among the top two van der Waals layers. This theory can be validated by the position- and field-dependent gap in future surface spectroscopy measurements. Our work suggests suppressing related defects in samples to realize the quantum anomalous Hall insulator or axion insulator at zero fields.
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Affiliation(s)
- Hengxin Tan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
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11
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Majchrzak PE, Liu Y, Volckaert K, Biswas D, Sahoo C, Puntel D, Bronsch W, Tuniz M, Cilento F, Pan XC, Liu Q, Chen YP, Ulstrup S. Van der Waals Engineering of Ultrafast Carrier Dynamics in Magnetic Heterostructures. NANO LETTERS 2023; 23:414-421. [PMID: 36607246 DOI: 10.1021/acs.nanolett.2c03075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Heterostructures composed of the intrinsic magnetic topological insulator MnBi2Te4 and its nonmagnetic counterpart Bi2Te3 host distinct surface electronic band structures depending on the stacking order and exposed termination. Here, we probe the ultrafast dynamical response of MnBi2Te4 and MnBi4Te7 following near-infrared optical excitation using time- and angle-resolved photoemission spectroscopy and disentangle surface from bulk dynamics based on density functional theory slab calculations of the surface-projected electronic structure. We gain access to the out-of-equilibrium charge carrier populations of both MnBi2Te4 and Bi2Te3 surface terminations of MnBi4Te7, revealing an instantaneous occupation of states associated with the Bi2Te3 surface layer followed by carrier extraction into the adjacent MnBi2Te4 layers with a laser fluence-tunable delay of up to 350 fs. The ensuing thermal relaxation processes are driven by phonon scattering with significantly slower relaxation times in the magnetic MnBi2Te4 septuple layers. The observed competition between interlayer charge transfer and intralayer phonon scattering demonstrates a method to control ultrafast charge transfer processes in MnBi2Te4-based van der Waals compounds.
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Affiliation(s)
- Paulina Ewa Majchrzak
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Yuntian Liu
- Department of Physics and Shenzhen Institute for Quantum Science and Engineering (SIQSE), Southern University of Science and Technology, Shenzhen 518055, China
| | - Klara Volckaert
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Deepnarayan Biswas
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Chakradhar Sahoo
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Denny Puntel
- Dipartimento di Fisica, Università degli Studi di Trieste, 34127 Trieste, Italy
| | - Wibke Bronsch
- Elettra - Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Italy
| | - Manuel Tuniz
- Dipartimento di Fisica, Università degli Studi di Trieste, 34127 Trieste, Italy
| | | | - Xing-Chen Pan
- Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Qihang Liu
- Department of Physics and Shenzhen Institute for Quantum Science and Engineering (SIQSE), Southern University of Science and Technology, Shenzhen 518055, China
| | - Yong P Chen
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
- Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Department of Physics and Astronomy, School of Electrical and Computer Engineering, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
| | - Søren Ulstrup
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
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12
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Yan C, Zhu Y, Miao L, Fernandez-Mulligan S, Green E, Mei R, Tan H, Yan B, Liu CX, Alem N, Mao Z, Yang S. Delicate Ferromagnetism in MnBi 6Te 10. NANO LETTERS 2022; 22:9815-9822. [PMID: 36315185 PMCID: PMC9801432 DOI: 10.1021/acs.nanolett.2c02500] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/27/2022] [Indexed: 06/16/2023]
Abstract
Tailoring magnetic orders in topological insulators is critical to the realization of topological quantum phenomena. An outstanding challenge is to find a material where atomic defects lead to tunable magnetic orders while maintaining a nontrivial topology. Here, by combining magnetization measurements, angle-resolved photoemission spectroscopy, and transmission electron microscopy, we reveal disorder-enabled, tunable magnetic ground states in MnBi6Te10. In the ferromagnetic phase, an energy gap of 15 meV is resolved at the Dirac point on the MnBi2Te4 termination. In contrast, antiferromagnetic MnBi6Te10 exhibits gapless topological surface states on all terminations. Transmission electron microscopy and magnetization measurements reveal substantial Mn vacancies and Mn migration in ferromagnetic MnBi6Te10. We provide a conceptual framework where a cooperative interplay of these defects drives a delicate change of overall magnetic ground state energies and leads to tunable magnetic topological orders. Our work provides a clear pathway for nanoscale defect-engineering toward the realization of topological quantum phases.
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Affiliation(s)
- Chenhui Yan
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois60637, United States
| | - Yanglin Zhu
- Department
of Physics, Pennsylvania State University, University Park, State College, Pennsylvania16802, United States
| | - Leixin Miao
- Department
of Materials Science and Engineering, The
Pennsylvania State University, University Park, State College, Pennsylvania16802, United States
| | | | - Emanuel Green
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois60637, United States
| | - Ruobing Mei
- Department
of Physics, Pennsylvania State University, University Park, State College, Pennsylvania16802, United States
| | - Hengxin Tan
- Department
of Condensed Matter Physics, Weizmann Institute
of Science, Rehovot7610001, Israel
| | - Binghai Yan
- Department
of Condensed Matter Physics, Weizmann Institute
of Science, Rehovot7610001, Israel
| | - Chao-Xing Liu
- Department
of Physics, Pennsylvania State University, University Park, State College, Pennsylvania16802, United States
| | - Nasim Alem
- Department
of Materials Science and Engineering, The
Pennsylvania State University, University Park, State College, Pennsylvania16802, United States
| | - Zhiqiang Mao
- Department
of Physics, Pennsylvania State University, University Park, State College, Pennsylvania16802, United States
| | - Shuolong Yang
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois60637, United States
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13
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Lei Y, Zhang T, Lin YC, Granzier-Nakajima T, Bepete G, Kowalczyk DA, Lin Z, Zhou D, Schranghamer TF, Dodda A, Sebastian A, Chen Y, Liu Y, Pourtois G, Kempa TJ, Schuler B, Edmonds MT, Quek SY, Wurstbauer U, Wu SM, Glavin NR, Das S, Dash SP, Redwing JM, Robinson JA, Terrones M. Graphene and Beyond: Recent Advances in Two-Dimensional Materials Synthesis, Properties, and Devices. ACS NANOSCIENCE AU 2022; 2:450-485. [PMID: 36573124 PMCID: PMC9782807 DOI: 10.1021/acsnanoscienceau.2c00017] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 12/30/2022]
Abstract
Since the isolation of graphene in 2004, two-dimensional (2D) materials research has rapidly evolved into an entire subdiscipline in the physical sciences with a wide range of emergent applications. The unique 2D structure offers an open canvas to tailor and functionalize 2D materials through layer number, defects, morphology, moiré pattern, strain, and other control knobs. Through this review, we aim to highlight the most recent discoveries in the following topics: theory-guided synthesis for enhanced control of 2D morphologies, quality, yield, as well as insights toward novel 2D materials; defect engineering to control and understand the role of various defects, including in situ and ex situ methods; and properties and applications that are related to moiré engineering, strain engineering, and artificial intelligence. Finally, we also provide our perspective on the challenges and opportunities in this fascinating field.
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Affiliation(s)
- Yu Lei
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Institute
of Materials Research, Tsinghua Shenzhen
International Graduate School, Shenzhen, Guangdong 518055, China,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Tianyi Zhang
- Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yu-Chuan Lin
- Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Tomotaroh Granzier-Nakajima
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - George Bepete
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Dorota A. Kowalczyk
- Department
of Solid State Physics, Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, Lodz 90-236, Poland
| | - Zhong Lin
- Department
of Physics, University of Washington, Seattle, Washington 98195, United States
| | - Da Zhou
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Thomas F. Schranghamer
- Department
of Engineering Science and Mechanics, Pennsylvania
State University, University Park, Pennsylvania 16802, United States
| | - Akhil Dodda
- Department
of Engineering Science and Mechanics, Pennsylvania
State University, University Park, Pennsylvania 16802, United States
| | - Amritanand Sebastian
- Department
of Engineering Science and Mechanics, Pennsylvania
State University, University Park, Pennsylvania 16802, United States
| | - Yifeng Chen
- Department
of Materials Science and Engineering, National
University of Singapore, 9 Engineering Drive, Singapore 117456, Singapore
| | - Yuanyue Liu
- Texas
Materials Institute and Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | | | - Thomas J. Kempa
- Department
of Chemistry, Johns Hopkins University, Baltimore, Maryland 21287, United States
| | - Bruno Schuler
- nanotech@surfaces
Laboratory, Empa − Swiss Federal
Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Mark T. Edmonds
- School
of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
| | - Su Ying Quek
- Department
of Materials Science and Engineering, National
University of Singapore, 9 Engineering Drive, Singapore 117456, Singapore
| | - Ursula Wurstbauer
- Institute
of Physics, University of Münster, Wilhelm-Klemm-Str. 10, Münster 48149, Germany
| | - Stephen M. Wu
- Department
of Electrical and Computer Engineering & Department of Physics
and Astronomy, University of Rochester, Rochester, New York 14627, United States
| | - Nicholas R. Glavin
- Air
Force
Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Dayton, Ohio 45433, United States
| | - Saptarshi Das
- Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Engineering Science and Mechanics, Pennsylvania
State University, University Park, Pennsylvania 16802, United States
| | - Saroj Prasad Dash
- Department
of Microtechnology and Nanoscience, Chalmers
University of Technology, Göteborg SE-412 96, Sweden
| | - Joan M. Redwing
- Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Joshua A. Robinson
- Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States,
| | - Mauricio Terrones
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Research
Initiative for Supra-Materials and Global Aqua Innovation Center, Shinshu University, 4-17-1Wakasato, Nagano 380-8553, Japan,
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14
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Padmanabhan H, Stoica VA, Kim PK, Poore M, Yang T, Shen X, Reid AH, Lin MF, Park S, Yang J, Wang HH, Koocher NZ, Puggioni D, Georgescu AB, Min L, Lee SH, Mao Z, Rondinelli JM, Lindenberg AM, Chen LQ, Wang X, Averitt RD, Freeland JW, Gopalan V. Large Exchange Coupling Between Localized Spins and Topological Bands in MnBi 2 Te 4. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2202841. [PMID: 36189841 DOI: 10.1002/adma.202202841] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 09/21/2022] [Indexed: 06/16/2023]
Abstract
Magnetism in topological materials creates phases exhibiting quantized transport phenomena with potential technological applications. The emergence of such phases relies on strong interaction between localized spins and the topological bands, and the consequent formation of an exchange gap. However, this remains experimentally unquantified in intrinsic magnetic topological materials. Here, this interaction is quantified in MnBi2 Te4 , a topological insulator with intrinsic antiferromagnetism. This is achieved by optically exciting Bi-Te p states comprising the bulk topological bands and interrogating the consequent Mn 3d spin dynamics, using a multimodal ultrafast approach. Ultrafast electron scattering and magneto-optic measurements show that the p states demagnetize via electron-phonon scattering at picosecond timescales. Despite being energetically decoupled from the optical excitation, the Mn 3d spins, probed by resonant X-ray scattering, are observed to disorder concurrently with the p spins. Together with atomistic simulations, this reveals that the exchange coupling between localized spins and the topological bands is at least 100 times larger than the superexchange interaction, implying an optimal exchange gap of at least 25 meV in the surface states. By quantifying this exchange coupling, this study validates the materials-by-design strategy of utilizing localized magnetic order to manipulate topological phases, spanning static to ultrafast timescales.
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Affiliation(s)
- Hari Padmanabhan
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Vladimir A Stoica
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Peter K Kim
- Department of Physics, University of California San Diego, La Jolla, CA, 92093, USA
| | - Maxwell Poore
- Department of Physics, University of California San Diego, La Jolla, CA, 92093, USA
| | - Tiannan Yang
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Alexander H Reid
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Ming-Fu Lin
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Suji Park
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Jie Yang
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Huaiyu Hugo Wang
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Nathan Z Koocher
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Danilo Puggioni
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Alexandru B Georgescu
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Lujin Min
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Seng Huat Lee
- 2D Crystal Consortium, Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Physics, Penn State University, University Park, PA, 16802, USA
| | - Zhiqiang Mao
- 2D Crystal Consortium, Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Physics, Penn State University, University Park, PA, 16802, USA
| | - James M Rondinelli
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Aaron M Lindenberg
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Department of Materials Science and Engineering, Stanford University, Menlo Park, CA, 94305, USA
| | - Long-Qing Chen
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Xijie Wang
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Richard D Averitt
- Department of Physics, University of California San Diego, La Jolla, CA, 92093, USA
| | - John W Freeland
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Venkatraman Gopalan
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
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15
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Visualizing the interplay of Dirac mass gap and magnetism at nanoscale in intrinsic magnetic topological insulators. Proc Natl Acad Sci U S A 2022; 119:e2207681119. [PMID: 36215491 PMCID: PMC9586289 DOI: 10.1073/pnas.2207681119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In intrinsic magnetic topological insulators, Dirac surface-state gaps are prerequisites for quantum anomalous Hall and axion insulating states. Unambiguous experimental identification of these gaps has proved to be a challenge, however. Here, we use molecular beam epitaxy to grow intrinsic MnBi2Te4 thin films. Using scanning tunneling microscopy/spectroscopy, we directly visualize the Dirac mass gap and its disappearance below and above the magnetic order temperature. We further reveal the interplay of Dirac mass gaps and local magnetic defects. We find that, in high defect regions, the Dirac mass gap collapses. Ab initio and coupled Dirac cone model calculations provide insight into the microscopic origin of the correlation between defect density and spatial gap variations. This work provides unambiguous identification of the Dirac mass gap in MnBi2Te4 and, by revealing the microscopic origin of its gap variation, establishes a material design principle for realizing exotic states in intrinsic magnetic topological insulators.
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16
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Ge W, Kim J, Chan YT, Vanderbilt D, Yan J, Wu W. Direct Visualization of Surface Spin-Flip Transition in MnBi_{4}Te_{7}. PHYSICAL REVIEW LETTERS 2022; 129:107204. [PMID: 36112444 DOI: 10.1103/physrevlett.129.107204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 06/23/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
We report direct visualization of spin-flip transition of the surface layer in antiferromagnet MnBi_{4}Te_{7}, a natural superlattice of alternating MnBi_{2}Te_{4} and Bi_{2}Te_{3} layers, using cryogenic magnetic force microscopy (MFM). The observation of magnetic contrast across domain walls and step edges confirms that the antiferromagnetic order persists to the surface layers. The magnetic field dependence of the MFM images reveals that the surface magnetic layer undergoes a first-order spin-flip transition at a magnetic field that is lower than the bulk transition, in excellent agreement with a revised Mills model. Our analysis suggests no reduction of the order parameter in the surface magnetic layer, implying robust ferromagnetism in the single-layer limit. The direct visualization of surface spin-flip transition not only opens up exploration of surface metamagnetic transitions in layered antiferromagnets, but also provides experimental support for realizing quantized transport in ultrathin films of MnBi_{4}Te_{7} and other natural superlattice topological magnets.
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Affiliation(s)
- Wenbo Ge
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Jinwoong Kim
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Ying-Ting Chan
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - David Vanderbilt
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Jiaqiang Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Weida Wu
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
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17
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Chen J, Xu W, Tan Z, Pan Z, Zhu P, Liao ZM, Yu D. Superconducting Proximity in Intrinsic Magnetic Topological Insulator MnBi 2Te 4-NbN Hybrid Device Modulated by Coulomb Blockade Effect. NANO LETTERS 2022; 22:6484-6491. [PMID: 35926195 DOI: 10.1021/acs.nanolett.2c00948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The combination of nontrivial topology, magnetism, and superconductivity could offer the potential to realize exotic excitations of quasiparticles. MnBi2Te4, as an intrinsic magnetic topological insulator, may be a good platform to create Majorana fermions if coupled to an s-wave superconductor. Here, we report the transport properties of a MnBi2Te4-NbN hybrid device. This device exhibits clear Coulomb blockade oscillations. We observe a large zero-bias conductance peak that exists over considerable changes in gate voltage, magnetic field, and temperature, which is interpreted as a not fully developed supercurrent. The zero-bias peak shows a nonmonotonic evolution with a magnetic field and an abrupt π phase shift with changing temperature. Zero-energy bound states and a topological phase transition may exist in this hybrid system. Our results provide the first experimental investigation into the properties of the intrinsic magnetic topological insulator/superconductor hybrid structures modulated by the Coulomb blockade effect.
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Affiliation(s)
- Jingjing Chen
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wenzheng Xu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Zhenbing Tan
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
| | - Zhencun Pan
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Pengfei Zhu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Zhi-Min Liao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Dapeng Yu
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy, Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
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18
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McLaughlin NJ, Hu C, Huang M, Zhang S, Lu H, Yan GQ, Wang H, Tserkovnyak Y, Ni N, Du CR. Quantum Imaging of Magnetic Phase Transitions and Spin Fluctuations in Intrinsic Magnetic Topological Nanoflakes. NANO LETTERS 2022; 22:5810-5817. [PMID: 35816128 DOI: 10.1021/acs.nanolett.2c01390] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Topological materials featuring exotic band structures, unconventional current flow patterns, and emergent organizing principles offer attractive platforms for the development of next-generation transformative quantum electronic technologies. The family of MnBi2Te4 (Bi2Te3)n materials is naturally relevant in this context due to their nontrivial band topology, tunable magnetism, and recently discovered extraordinary quantum transport behaviors. Despite numerous pioneering studies to date, the local magnetic properties of MnBi2Te4 (Bi2Te3)n remain an open question, hindering a comprehensive understanding of their fundamental material properties. Exploiting nitrogen-vacancy (NV) centers in diamond, we report nanoscale quantum imaging of the magnetic phase transitions and spin fluctuations in exfoliated MnBi4Te7 flakes, revealing the underlying spin transport physics and magnetic domains at the nanoscale. Our results highlight the unique advantage of NV centers in exploring the magnetic properties of emergent quantum materials, opening new opportunities for investigating the interplay between topology and magnetism.
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Affiliation(s)
- Nathan J McLaughlin
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Chaowei Hu
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, United States
| | - Mengqi Huang
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Shu Zhang
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, United States
| | - Hanyi Lu
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Gerald Q Yan
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
| | - Hailong Wang
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, California 92093, United States
| | - Yaroslav Tserkovnyak
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, United States
| | - Ni Ni
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, United States
| | - Chunhui Rita Du
- Department of Physics, University of California, San Diego, La Jolla, California 92093, United States
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, California 92093, United States
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19
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Xu HK, Gu M, Fei F, Gu YS, Liu D, Yu QY, Xue SS, Ning XH, Chen B, Xie H, Zhu Z, Guan D, Wang S, Li Y, Liu C, Liu Q, Song F, Zheng H, Jia J. Observation of Magnetism-Induced Topological Edge State in Antiferromagnetic Topological Insulator MnBi 4Te 7. ACS NANO 2022; 16:9810-9818. [PMID: 35695549 DOI: 10.1021/acsnano.2c03622] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Breaking time reversal symmetry in a topological insulator may lead to quantum anomalous Hall effect and axion insulator phase. MnBi4Te7 is a recently discovered antiferromagnetic topological insulator with TN ∼ 12.5 K, which is composed of an alternatively stacked magnetic layer (MnBi2Te4) and nonmagnetic layer (Bi2Te3). By means of scanning tunneling spectroscopy, we clearly observe the electronic state present at a step edge of a magnetic MnBi2Te4 layer but absent at nonmagnetic Bi2Te3 layers at 4.5 K. Furthermore, we find that as the temperature rises above TN the edge state vanishes, while the point defect induced state persists upon an increase in temperature. These results confirm the observation of magnetism-induced edge states. Our analysis based on an axion insulator theory reveals that the nontrivial topological nature of the observed edge state.
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Affiliation(s)
- Hao-Ke Xu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Mingqiang Gu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Fucong Fei
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, China
| | - Yi-Sheng Gu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dang Liu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiao-Yan Yu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Sha-Sha Xue
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xu-Hui Ning
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bo Chen
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, China
| | - Hangkai Xie
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, China
| | - Zhen Zhu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dandan Guan
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shiyong Wang
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yaoyi Li
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Canhua Liu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qihang Liu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Fengqi Song
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, China
| | - Hao Zheng
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jinfeng Jia
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
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20
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Liang A, Chen C, Zheng H, Xia W, Huang K, Wei L, Yang H, Chen Y, Zhang X, Xu X, Wang M, Guo Y, Yang L, Liu Z, Chen Y. Approaching a Minimal Topological Electronic Structure in Antiferromagnetic Topological Insulator MnBi 2Te 4 via Surface Modification. NANO LETTERS 2022; 22:4307-4314. [PMID: 35604392 DOI: 10.1021/acs.nanolett.1c04930] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The topological electronic structure plays a central role in the nontrivial physical properties in topological quantum materials. A minimal, "hydrogen-atom-like" topological electronic structure is desired for research. In this work, we demonstrate an effort toward the realization of such a system in the intrinsic magnetic topological insulator MnBi2Te4, by manipulating the topological surface state (TSS) via surface modification. Using high resolution laser- and synchrotron-based angle-resolved photoemission spectroscopy (ARPES), we found the TSS in MnBi2Te4 is heavily hybridized with a trivial Rashba-type surface state (RSS), which could be efficiently removed by the in situ surface potassium (K) dosing. By employing multiple experimental methods to characterize K dosed surface, we attribute such a modification to the electrochemical reactions of K clusters on the surface. Our work not only gives a clear band assignment in MnBi2Te4 but also provides possible new routes in accentuating the topological behavior in the magnetic topological quantum materials.
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Affiliation(s)
- Aiji Liang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Cheng Chen
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, U.K
| | - Huijun Zheng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Kui Huang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Liyang Wei
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Haifeng Yang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yujie Chen
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Xin Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xuguang Xu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Meixiao Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Lexian Yang
- 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
| | - Zhongkai Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Yulin Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, U.K
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
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21
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Ye C, Xie X, Lv W, Huang K, Yang AJ, Jiang S, Liu X, Zhu D, Qiu X, Tong M, Zhou T, Hsu CH, Chang G, Lin H, Li P, Yang K, Wang Z, Jiang T, Renshaw Wang X. Nonreciprocal Transport in a Bilayer of MnBi 2Te 4 and Pt. NANO LETTERS 2022; 22:1366-1373. [PMID: 35073094 DOI: 10.1021/acs.nanolett.1c04756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
MnBi2Te4 (MBT) is the first intrinsic magnetic topological insulator with the interaction of spin-momentum locked surface electrons and intrinsic magnetism, and it exhibits novel magnetic and topological phenomena. Recent studies suggested that the interaction of electrons and magnetism can be affected by the Mn-doped Bi2Te3 phase at the surface due to inevitable structural defects. Here, we report an observation of nonreciprocal transport, that is, current-direction-dependent resistance, in a bilayer composed of antiferromagnetic MBT and nonmagnetic Pt. The emergence of the nonreciprocal response below the Néel temperature confirms a correlation between nonreciprocity and intrinsic magnetism in the surface state of MBT. The angular dependence of the nonreciprocal transport indicates that nonreciprocal response originates from the asymmetry scattering of electrons at the surface of MBT mediated by magnon. Our work provides an insight into nonreciprocity arising from the correlation between magnetism and Dirac surface electrons in intrinsic magnetic topological insulators.
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Affiliation(s)
- Chen Ye
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link 637371, Singapore
| | - Xiangnan Xie
- State Key Laboratory of High Performance Computing, College of Computer Science and Technology, National University of Defense Technology, Changsha 410073, P.R. China
| | - Wenxing Lv
- Physics Laboratory, Industrial Training Center, Shenzhen Polytechnic, Shenzhen, Guangdong 518055, P.R. China
| | - Ke Huang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link 637371, Singapore
| | - Allen Jian Yang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link 637371, Singapore
| | - Sicong Jiang
- Department of NanoEngineering and Program of Chemical Engineering, University of California San Diego, La Jolla, California 92093-0448, United States
- Program of Materials Science and Engineering, University of California San Diego, La Jolla, California 92093-0418, United States
| | - Xue Liu
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link 637371, Singapore
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Dapeng Zhu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, P.R. China
- Beihang-Goertek Joint Microelectronics Institute, Qingdao Research Institute, Beihang University, Qingdao 266000, P.R. China
| | - Xuepeng Qiu
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and School of Physics Science and Engineering, Tongji University, Shanghai 200092, P.R. China
| | - Mingyu Tong
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, P.R. China
| | - Tong Zhou
- State Key Laboratory of High Performance Computing, College of Computer Science and Technology, National University of Defense Technology, Changsha 410073, P.R. China
| | - Chuang-Han Hsu
- Insitute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Guoqing Chang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link 637371, Singapore
| | - Hsin Lin
- Insitute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Peisen Li
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, P.R. China
| | - Kesong Yang
- Department of NanoEngineering and Program of Chemical Engineering, University of California San Diego, La Jolla, California 92093-0448, United States
- Program of Materials Science and Engineering, University of California San Diego, La Jolla, California 92093-0418, United States
| | - Zhenyu Wang
- State Key Laboratory of High Performance Computing, College of Computer Science and Technology, National University of Defense Technology, Changsha 410073, P.R. China
- National Innovation Institute of Defense Technology, Academy of Military Sciences PLA China, Beijing 100010, P.R. China
- Beijing Academy of Quantum Information Sciences, Beijing 100084, P.R. China
| | - Tian Jiang
- State Key Laboratory of High Performance Computing, College of Computer Science and Technology, National University of Defense Technology, Changsha 410073, P.R. China
- Beijing Institute for Advanced Study, National University of Defense Technology, Changsha 410073, P.R. China
| | - Xiao Renshaw Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link 637371, Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
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22
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Wu M, Tu D, Nie Y, Miao S, Gao W, Han Y, Zhu X, Zhou J, Ning W, Tian M. Novel π/2-Periodic Planar Hall Effect Due to Orbital Magnetic Moments in MnBi 2Te 4. NANO LETTERS 2022; 22:73-80. [PMID: 34962398 DOI: 10.1021/acs.nanolett.1c03232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The Berry curvature and orbital magnetic moment (OMM) come from either inversion symmetry or time-reversal symmetry breaking in quantum materials. Here, we demonstrate the significance of OMMs and Berry curvature in planar Hall effect (PHE) in antiferromagnetic topological insulator MnBi2Te4 flakes. We observe a PHE with period of π and positive magnitude at low fields, resembling the PHE of the surface states in nonmagnetic topological insulators. Remarkably, a novel predominant PHE with period of π/2 and negative magnitude emerges below the Néel temperature with B > 10 T. Our theoretical calculations reveal that this unusual π/2-periodic PHE originates from the topological OMMs of bulk Dirac electrons. Moreover, the competition between the contributions from the bulk and the surface states leads to nontrivial evolutions of PHE and anisotropic magnetoresistance. Our results reveal intriguing electromagnetic response due to the OMMs and also provide insight into the potential applications of magnetic topological insulators in spintronics.
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Affiliation(s)
- Min Wu
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
| | - Daifeng Tu
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
- Department of Physics, University of Science and Technology of China, Hefei 230026, P.R. China
| | - Yong Nie
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
- Department of Physics, University of Science and Technology of China, Hefei 230026, P.R. China
| | - Shaopeng Miao
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
- Department of Physics, University of Science and Technology of China, Hefei 230026, P.R. China
| | - Wenshuai Gao
- Department of Physics, School of Physics and Materials Science, Anhui University, Hefei 230601, P.R. China
| | - Yuyan Han
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
| | - Xiangde Zhu
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
| | - Jianhui Zhou
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
| | - Wei Ning
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
| | - Mingliang Tian
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P.R. China
- Department of Physics, School of Physics and Materials Science, Anhui University, Hefei 230601, P.R. China
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23
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Zhong H, Bao C, Wang H, Li J, Yin Z, Xu Y, Duan W, Xia TL, Zhou S. Light-Tunable Surface State and Hybridization Gap in Magnetic Topological Insulator MnBi 8Te 13. NANO LETTERS 2021; 21:6080-6086. [PMID: 34242038 DOI: 10.1021/acs.nanolett.1c01448] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
MnBi8Te13 is an intrinsic ferromagnetic (FM) topological insulator with different complex surface terminations. Resolving the electronic structures of different termination surfaces and manipulation of the electronic state are important. Here, by using micrometer spot time- and angle-resolved photoemission spectroscopy (μ-TrARPES), we resolve the electronic structures and reveal the ultrafast dynamics upon photoexcitation. Photoinduced filling of the surface state hybridization gap is observed for the Bi2Te3 quintuple layer directly above MnBi2Te4 accompanied by a nontrivial shift of the surface state, suggesting light-tunable interlayer interaction. Relaxation of photoexcited electrons and holes is observed within 1-2 ps. Our work reveals photoexcitation as a potential control knob for tailoring the interlayer interaction and surface state of MnBi8Te13.
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Affiliation(s)
- Haoyuan Zhong
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P. R. China
| | - Changhua Bao
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P. R. China
| | - Huan Wang
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, P. R. China
| | - Jiaheng Li
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P. R. China
| | - Zichen Yin
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P. R. China
| | - Yong Xu
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P. R. China
- Frontier Science Center for Quantum Information, Beijing 100084, P. R. China
| | - Wenhui Duan
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P. R. China
- Frontier Science Center for Quantum Information, Beijing 100084, P. R. China
| | - Tian-Long Xia
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, P. R. China
| | - Shuyun Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P. R. China
- Frontier Science Center for Quantum Information, Beijing 100084, P. R. China
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24
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Huan S, Zhang S, Jiang Z, Su H, Wang H, Zhang X, Yang Y, Liu Z, Wang X, Yu N, Zou Z, Shen D, Liu J, Guo Y. Multiple Magnetic Topological Phases in Bulk van der Waals Crystal MnSb_{4}Te_{7}. PHYSICAL REVIEW LETTERS 2021; 126:246601. [PMID: 34213928 DOI: 10.1103/physrevlett.126.246601] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
The magnetic van der Waals crystals MnBi_{2}Te_{4}/(Bi_{2}Te_{3})_{n} have drawn significant attention due to their rich topological properties and the tunability by external magnetic field. Although the MnBi_{2}Te_{4}/(Bi_{2}Te_{3})_{n} family have been intensively studied in the past few years, their close relatives, the MnSb_{2}Te_{4}/(Sb_{2}Te_{3})_{n} family, remain much less explored. In this work, combining magnetotransport measurements, angle-resolved photoemission spectroscopy, and first principles calculations, we find that MnSb_{4}Te_{7}, the n=1 member of the MnSb_{2}Te_{4}/(Sb_{2}Te_{3})_{n} family, is a magnetic topological system with versatile topological phases that can be manipulated by both carrier doping and magnetic field. Our calculations unveil that its A-type antiferromagnetic (AFM) ground state stays in a Z_{2} AFM topological insulator phase, which can be converted to an inversion-symmetry-protected axion insulator phase when in the ferromagnetic (FM) state. Moreover, when this system in the FM phase is slightly carrier doped on either the electron or hole side, it becomes a Weyl semimetal with multiple Weyl nodes in the highest valence bands and lowest conduction bands, which are manifested by the measured notable anomalous Hall effect. Our work thus introduces a new magnetic topological material with different topological phases that are highly tunable by carrier doping or magnetic field.
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Affiliation(s)
- Shuchun Huan
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Shihao Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zhicheng Jiang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
| | - Hao Su
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Hongyuan Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xin Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yichen Yang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
| | - Zhengtai Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
| | - Xia Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Analytical Instrumentation Center, School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Na Yu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Analytical Instrumentation Center, School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zhiqiang Zou
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Analytical Instrumentation Center, School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Dawei Shen
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianpeng Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 201210, China
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
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25
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Abstract
Introducing magnetism into topological insulators breaks time-reversal symmetry, and the magnetic exchange interaction can open a gap in the otherwise gapless topological surface states. This allows various novel topological quantum states to be generated, including the quantum anomalous Hall effect (QAHE) and axion insulator states. Magnetic doping and magnetic proximity are viewed as being useful means of exploring the interaction between topology and magnetism. However, the inhomogeneity of magnetic doping leads to complicated magnetic ordering and small exchange gaps, and consequently the observed QAHE appears only at ultralow temperatures. Therefore, intrinsic magnetic topological insulators are highly desired for increasing the QAHE working temperature and for investigating topological quantum phenomena further. The realization and characterization of such systems are essential for both fundamental physics and potential technical revolutions. This review summarizes recent research progress in intrinsic magnetic topological insulators, focusing mainly on the antiferromagnetic topological insulator MnBi2Te4 and its family of materials. van der Waals material MnBi2Te4 is an intrinsic antiferromagnetic topological insulator Under moderate magnetic field, MnBi2Te4 may become a magnetic Weyl semimetal MnBi2Te4 and its family of materials have brought great progress in studying novel topological quantum states Quantum anomalous Hall effect above the liquid-nitrogen temperature can be expected in MnBi2Te4-related systems
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26
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Perez-Piskunow PM, Roche S. Hinge Spin Polarization in Magnetic Topological Insulators Revealed by Resistance Switch. PHYSICAL REVIEW LETTERS 2021; 126:167701. [PMID: 33961483 DOI: 10.1103/physrevlett.126.167701] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
We report on the possibility of detecting hinge spin polarization in magnetic topological insulators by resistance measurements. By implementing a three-dimensional model of magnetic topological insulators into a multiterminal device with ferromagnetic contacts near the top surface, local spin features of the chiral edge modes are unveiled. We find local spin polarization at the hinges that inverts the sign between the top and bottom surfaces. At the opposite edge, the topological state with inverted spin polarization propagates in the reverse direction. A large resistance switch between forward and backward propagating states is obtained, driven by the matching between the spin polarized hinges and the ferromagnetic contacts. This feature is general to the ferromagnetic, antiferromagnetic, and canted antiferromagnetic phases, and enables the design of spin-sensitive devices, with the possibility of reversing the hinge spin polarization of the currents.
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Affiliation(s)
- Pablo M Perez-Piskunow
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
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- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain and ICREA-Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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