Chern Number Tunable Quantum Anomalous Hall Effect in Compensated Antiferromagnets
Wenhao Liang, Zeyu Li, Jiaqi An, Yafei Ren, Zhenhua Qiao, Qian Niu
Abstract
We propose to realize the quantum anomalous Hall effect (QAHE) in two-dimensional compensated antiferromagnets without net spin magnetization. We consider antiferromagnetic MnBi_{2}Te_{4} as a concrete example. By breaking the parity-time (PT) symmetry of even-layer MnBi_{2}Te_{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 symmetry-tetralayer MnBi_{2}Te_{4} can host a Chern number |C|=1. Such spin configuration can be stabilized by pinning the spin orientations of the surfaces. 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. In addition, we reveal that the edge states are layer selective and primarily located at the boundaries of the bottom and top layers. Our Letter 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.