English

Chern Number Tunable Quantum Anomalous Hall Effect in Compensated Antiferromagnets

Mesoscale and Nanoscale Physics 2025-07-08 v2

Abstract

We propose to realize the quantum anomalous Hall effect (QAHE) in two-dimensional compensated antiferromagnets without net spin magnetization.} We consider antiferromagnetic MnBi2_2Te4_4 as a concrete example. \textcolor{blue}{By breaking the parity-time (PT\mathcal{PT}) symmetry of even-layer MnBi2_2Te4_4, we find that the system can host the QAHE with a nonzero Chern number.} We show that by controlling the antiferromagnetic spin configuration, for example, down/up/up/down that breaks PT\mathcal{PT} symmetry, tetralayer MnBi2_2Te4_4 can host a Chern number C=1\mathcal{C}=-1. Such spin configuration can be stabilized by pinning the spin orientations of the surfaces. \textcolor{blue}{Furthermore, via tuning the on-site orbital energy and vertical electric fields, we find rich QAHE phases with tunable Chern number of C=1,2,3|\mathcal{C}|=1, 2, 3. In addition, we reveal that the edge states are layer-selective and primarily locate at the boundaries of the bottom and top layers. Our work not only proposes a scheme to realize Chern number tunable QAHE in antiferromagnets without net spin magnetization, but also provides a platform for layer-selective dissipationless transport devices.

Keywords

Cite

@article{arxiv.2404.13305,
  title  = {Chern Number Tunable Quantum Anomalous Hall Effect in Compensated Antiferromagnets},
  author = {Wenhao Liang and Jiaqi An and Zeyu Li and Yafei Ren and Zhenhua Qiao and Qian Niu},
  journal= {arXiv preprint arXiv:2404.13305},
  year   = {2025}
}