Routes to quantum anomalous Hall effect from superlattice-like magnetic topological insulators

ORAL

Abstract

Recently, MnBi2Te4 thin films were observed to manifest the quantum anomalous Hall effect (QAHE) at a temperature of 4.5 K under magnetic field. By realizing a bulk MnBi4Te7 with alternating [MnBi2Te4] and [Bi2Te3] layers, we suggest that MnBi4Te7 is a Z2 antiferromagnetic topological insulator with a small out-of-plane saturation field of ~ 0.2 Tesla [1]. Using model Hamiltonian analysis and first-principle calculations, we then establish a topological phase diagram and map on it with different two-dimensional configurations, which is taken from the recently-grown magnetic topological insulators MnBi4Te7 and MnBi6Te10. These configurations manifest various topological phases, including quantum spin Hall effect with and without time-reversal symmetry, as well as QAHE. We then provide design principles to trigger QAHE by tuning experimentally accessible knobs, such as slab thickness and magnetization [2]. Our work reveals that superlattice-like magnetic topological insulators with tunable exchange interaction serve as an ideal platform to realize the long-sought QAHE in pristine compounds.
[1] arXiv:1905.02154 (2019)
[2] Phys. Rev. Lett. 123, 096401 (2019)

*This work was supported by the National Natural Science Foundation of China under Grant No. 11874195

–

Presenters

  • 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

Authors

  • 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

  • Hongyi Sun

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

  • Ni Ni

    • Univ of California Los Angeles
    • Physics, University of California, Los Angeles
    • Physics and Astronomy, UCLA
    • Department of Physics and Astronomy, University 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
    • Department of Physics and Astronomy, University of California, Los Angeles

  • Chaowei Hu

    • University of California, Los Angeles
    • Department of Physics and Astronomy, University of California, Los Angeles

  • Kyle Gordon

    • University of Colorado, Boulder
    • Physics, University of Colorado-Boulder

  • Daniel Dessau

    • Department of Physics, University of Colorado Boulder
    • University of Colorado, Boulder
    • Physics, University of Colorado-Boulder