Gapless surface Dirac cone and its possible origin in antiferromagnetic topological insulator MnBi<sub>2</sub>Te<sub>4</sub>

ORAL

Abstract

The recent discovered antiferromagnetic topological insulators in the Mn-Bi-Te family have rapidly drawn broad interest since its cleaved surface state is believed to be gapped, hosting the unprecedented axion states. However, we show by ARPES that a gapless Dirac cone at the (0001) surface of MnBi2Te4 exists inside the bulk band gap. Such unexpected surface state remains unchanged across the bulk Néel temperature, and is robust against severe surface degradation, indicating additional topological protection. Through symmetry analysis and ab initio calculations we consider different types of surface magneitc reconstruction as possible origins giving rise to such linear dispersion. Our results reveal that the intrinsic magnetic topological insulator hosts a rich platform to realize various topological phases, and thus pushed forward the comprehensive understanding of magnetic topological materials.

*Work at SUSTech was supported by the National Natural Science Foundation of China (NSFC) (Nos. 11504159 and 11874195), the Guangdong Innovative and Entrepreneurial Research Team Program (Nos. 2016ZT06D348 and 2017ZT07C062), etc. Work at UCLA was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0011978.

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Presenters

  • Chang Liu

    • physics, Southern University of Science and Technology
    • Physics, Southern University of Science and Technology
    • Southern University of Science and Technology

Authors

  • Yu-Jie Hao

    • Physics, Southern University of Science and Technology

  • Pengfei Liu

    • Physics, Shenzhen Institute for Quantum Science and Technology
    • Physics, Southern University of Science and Technology
    • Department of Physics, Southern University of Science and Technology

  • Yue Feng

    • Physics, Southern University of Science and Technology

  • Xiao-Ming Ma

    • physics, Southern University of Science and Technology
    • Physics, Southern University of Science and Technology
    • Southern University of Science and Technology

  • Eike F. Schwier

    • Hiroshima University
    • Hiroshima Synchrotron Radiation Center, Hiroshima University

  • Masashi Arita

    • Hiroshima University
    • Hiroshima Synchrotron Radiation Center, Hiroshima University

  • Shiv Kumar

    • Hiroshima Synchrotron Radiation Center, Hiroshima University

  • Chaowei Hu

    • Physics, University of California, Los Angeles
    • Physics and Astronomy, UCLA
    • Physics and Astronomy, Univerisity of California, Los Angeles
    • University of California, Los Angeles
    • Department of Physics and Astronomy and California NanoSystems Institute, University of California
    • Department of Physics and Astronomy and California Nano Systems Institute, University of California, Los Angeles, CA 90095, USA
    • University of California Los Angeles

  • Rui'e Lu

    • Physics, Southern University of Science and Technology
    • Southern University of Science and Technology

  • Meng Zeng

    • Physics, Southern University of Science and Technology
    • Southern University of Science and Technology

  • Yuan Wang

    • Physics, Southern University of Science and Technology

  • Zhanyang Hao

    • Physics, Southern University of Science and Technology

  • Hong-Yi Sun

    • Physics, Southern University of Science and Technology

  • Ke Zhang

    • Hiroshima Synchrotron Radiation Center, Hiroshima University

  • Jiawei Mei

    • Physics, Southern University of Science and Technology

  • Ni Ni

    • Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA
    • Physics and Astronomy, Univerisity of California, Los Angeles

  • Liusuo Wu

    • Physics, Southern University of Science and Technology

  • Kenya Shimada

    • Hiroshima University
    • Hiroshima Synchrotron Radiation Center, Hiroshima University

  • Chaoyu Chen

    • Physics, Southern University of Science and Technology
    • the school of Physics, Southern University of Science and Technology

  • Qihang Liu

    • physics, Southern University of Science and Technology
    • Physics, Shenzhen Institute for Quantum Science and Technology
    • Physics, Southern University of Science and Technology
    • Southern University of Science and Technology
    • Department of Physics, Southern University of Science and Technology

  • Chang Liu

    • physics, Southern University of Science and Technology
    • Physics, Southern University of Science and Technology
    • Southern University of Science and Technology