Switchable anomalous Hall effects in polar-stacked 2D antiferromagnet MnBi₂Te₄

Authors

Tengfei CaoFollow
Ding-Fu Shao, Chinese Academy of Sciences
Kai Huang, University of Nebraska-LincolnFollow
Gautam Gurung, University of Oxford
Evgeny Y. Tsymbal, University of Nebraska at LincolnFollow

Date of this Version

2023

Citation

Published in Nano Lett. 2023, 23, 3781−3787. DOI: 10.1021/acs.nanolett.3c00047

Comments

Used by permission.

Abstract

Van der Waals (vdW) assembly allows controlling symmetry of two-dimensional (2D) materials that determines their physical properties. Especially interesting is the recently demonstrated breaking inversion symmetry by polar layer stacking to realize novel electronic, magnetic, and transport properties of 2D vdW materials switchable by induced electric polarization. Here, based on symmetry analyses and density-functional calculations, we explore the emergence of the anomalous Hall effect (AHE) in antiferromagnetic MnBi2Te4 films assembled by polar layer stacking. We demonstrate that breaking 𝑃̂ 𝑇̂ symmetry in an MnBi₂Te₄ bilayer makes this 2D material magnetoelectric and produces a spontaneous AHE switchable by electric polarization. We find that reversable polarization at one of the interfaces in a three-layer MnBi₂Te₄ film drives a metal-insulator transition, as well as switching between an AHE and quantum AHE (QAHE). Finally, we predict that engineering an interlayer polarization in a three-layer MnBi₂Te₄ film allows converting MnBi2Te4 from a trivial insulator to a Chern insulator. Overall, our work emphasizes the emergence of quantum-transport phenomena in 2D vdW antiferromagnets by polar layer stacking, which do not exist in this material in the bulk or bulk-like thin-film forms.