APS Logo

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)

–

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