Persistent surface states with diminishing gap in MnBi2Te4/Bi2Te3 superlattice antiferromagnetic topological insulator

Lixuan Xu; Yuanhao Mao; Hongyuan Wang; Jiaheng Li; Yujie Chen; Yunyouyou Xia; Yiwei Li; Ding Pei; Jing Zhang; Huijun Zheng; Kui Huang; Chaofan Zhang; Shengtao Cui; Aiji Liang; Wei Xia; Hao Su; Sungwon Jung; Cephise Cacho; Meixiao Wang; Gang Li; Yong Xu; Yanfeng Guo; Lexian Yang; Zhongkai Liu; Yulin Chen; Mianheng Jiang

doi:10.1016/j.scib.2020.07.032

Persistent surface states with diminishing gap in MnBi₂Te₄/Bi₂Te₃ superlattice antiferromagnetic topological insulator

Sci Bull (Beijing). 2020 Dec 30;65(24):2086-2093. doi: 10.1016/j.scib.2020.07.032. Epub 2020 Jul 31.

Authors

Lixuan Xu¹, Yuanhao Mao², Hongyuan Wang³, Jiaheng Li⁴, Yujie Chen⁴, Yunyouyou Xia³, Yiwei Li⁵, Ding Pei⁵, Jing Zhang⁶, Huijun Zheng⁶, Kui Huang⁶, Chaofan Zhang², Shengtao Cui⁶, Aiji Liang⁷, Wei Xia⁸, Hao Su⁶, Sungwon Jung⁹, Cephise Cacho⁹, Meixiao Wang¹⁰, Gang Li¹⁰, Yong Xu¹¹, Yanfeng Guo⁶, Lexian Yang¹², Zhongkai Liu¹³, Yulin Chen¹⁴, Mianheng Jiang¹⁵

Affiliations

¹ Center for Excellence in Superconducting Electronics, State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; 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; University of Chinese Academy of Sciences, Beijing 100049, China.
² College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China.
³ School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai 201210, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.
⁵ Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, UK.
⁶ School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai 201210, China.
⁷ 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; Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁸ 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; University of Chinese Academy of Sciences, Beijing 100049, China.
⁹ Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK.
¹⁰ 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.
¹¹ 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; RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.
¹² 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. Electronic address: lxyang@tsinghua.edu.cn.
¹³ 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. Electronic address: liuzhk@shanghaitech.edu.cn.
¹⁴ 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; State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, UK. Electronic address: yulin.chen@physics.ox.ac.uk.
¹⁵ Center for Excellence in Superconducting Electronics, State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai 201210, China; University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 36732961
DOI: 10.1016/j.scib.2020.07.032

Abstract

Magnetic topological quantum materials (TQMs) provide a fertile ground for the emergence of fascinating topological magneto-electric effects. Recently, the discovery of intrinsic antiferromagnetic (AFM) topological insulator MnBi₂Te₄ that could realize quantized anomalous Hall effect and axion insulator phase ignited intensive study on this family of TQM compounds. Here, we investigated the AFM compound MnBi₄Te₇ where Bi₂Te₃ and MnBi₂Te₄ layers alternate to form a superlattice. Using spatial- and angle-resolved photoemission spectroscopy, we identified ubiquitous (albeit termination dependent) topological electronic structures from both Bi₂Te₃ and MnBi₂Te₄ terminations. Unexpectedly, while the bulk bands show strong temperature dependence correlated with the AFM transition, the topological surface states with a diminishing gap show negligible temperature dependence across the AFM transition. Together with the results of its sister compound MnBi₂Te₄, we illustrate important aspects of electronic structures and the effect of magnetic ordering in this family of magnetic TQMs.

Keywords: Electronic band structure; Magnetic topological insulator; Quantum anomalous Hall effect; Spatially resolved angle-resolved photoemission spectroscopy.