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MnBi<sub>2n</sub>Te<sub>3n+1</sub>: from intrinsic antiferromagnetic to ferromagnetic topological insulators

ORAL

Abstract

Magnetic topological insulators provide an important materials platform to explore emergent quantum phenomena. Recently, MnBi2Te4 was discovered to be the first material realization of a van der Waals (vdW) antiferromagnetic topological insulator (TI). In the two-dimensional (2D) limit, at a record high temperature of 4.5 K, MnBi2Te4 manifests the QAH effect in the forced ferromagnetic state above 12 T [1]. To realize the QAH effect at lower fields or even zero field, it is essential to search for ferromagnetic TIs or antiferromagnetic TIs with lower saturation fields. By reducing the interlayer magnetic exchange interaction through our rational design of the natural heterostructure consisting of the building blocks of [MnBi2Te4] septuple layers and [Bi2Te3] quintuple layers, I will show that this family of materials can be tuned from antiferromagnetic to ferromagnetic, providing a superior material platform to investigate various emergent phenomena arising from the interplay between magnetism and band topology [2,3].
[1] Y. deng, et. al, arxiv: 1904.11468 (2019)
[2] C. H, et. al, arxiv: 1905.02154 (2019)
[3] C. H, et. al, arxiv: 1910.12847 (2019)

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Presenters

  • 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

Authors

  • 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