Intertwined Topological and Magnetic Orders in Atomically Thin Chern Insulator MnBi<sub>2</sub>Te<sub>4</sub>

ORAL

Abstract

The interplay between band topology and magnetic order plays a key role in new quantum states of matter. MnBi2Te4, a crystalline topological van der Waals magnet, has recently emerged as an exciting platform for exploring Chern insulator physics. Its layered antiferromagnetic ground state was predicted to enable even-odd layer-number dependent topological states, while tunability of spin states via external magnetic field offers an interesting venue for observation of topological phase transitions. In this work by combination of magnetic circular dichroism, transport, and microwave impedance measurements (MIM) we investigate connection between bulk electronic structure, topological order, and magnetic states in thin flakes of MnBi2Te4. We establish one to one correspondence between spin state and Chern number in this material and observe band crossing, which is closing and reopening of bulk bandgap as a function of external magnetic field. Furthermore, we investigate Chern gap formation in MnBi2Te4 and its evolution as a function of temperature. Finally, we will discuss even-odd layer-number dependent effects on bulk electronic structure of MnBi2Te4 and Chern insulator state formation.

*Center for Programmable Quantum Materials, under award DE-SC0019443
DOE BES DE-SC0018171

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Presenters

  • Dmitry Ovchinnikov

    • Department of Physics, University of Washington
    • University of Washington

Authors

  • Dmitry Ovchinnikov

    • Department of Physics, University of Washington
    • University of Washington

  • Xiong Huang

    • University of California, Riverside

  • Zhong Lin

    • University of Washington

  • Zaiyao Fei

    • Department of Physics, University of Washington
    • University of Washington

  • Jiaqi Cai

    • University of Washington

  • Tiancheng Song

    • Department of Physics, University of Washington
    • University of Washington

  • Minhao He

    • Department of Physics, University of Washington
    • University of Washington

  • Qianni Jiang

    • University of Washington
    • Department of Physics, University of Washington
    • Physics, University of Washington

  • Chong Wang

    • Department of Physics, Carnegie Mellon University
    • Physics, Carnegie Mellon University
    • Carnegie Mellon University
    • Carnegie Mellon Univ

  • Hao Li

    • School of Materials Science and engineering, Tsinghua University
    • Tsinghua University

  • Yayu Wang

    • Tsinghua University
    • Department of Physics, Tsinghua University

  • Yang Wu

    • Department of Mechanical Engineering, Tsinghua University
    • Tsinghua University

  • Di Xiao

    • Carnegie Mellon Univ
    • Carnegie Mellon University
    • Department of Physics, Carnegie Mellon University
    • Physics, Carnegie Mellon University

  • Jiun-Haw Chu

    • University of Washington
    • Department of Physics, University of Washington, Seattle
    • Department of Physics, University of Washington
    • Physics, University of Washington

  • Jiaqiang Yan

    • Materials Science and Technology Division, Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • University of Tennessee
    • Oak Ridge National Lab
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Materials Science and Technology, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory, Materials Science and Technology Division

  • Cui-Zu Chang

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University
    • The Pennsylvania State University

  • Yongtao Cui

    • University of California, Riverside
    • Department of Physics and Astronomy, University of California, Riverside
    • University of California, Reverside

  • Xiaodong Xu

    • Physics, University of Washington
    • Department of Physics, University of Washington
    • University of Washington
    • Department of Physics, University of Washington, Seattle
    • University of Washington, Seattle