Quantum Anomalous Hall Effect in Perfectly Compensated Collinear Antiferromagnetic Thin Films

TL;DR

This paper demonstrates that the quantum anomalous Hall effect can occur in perfectly compensated collinear antiferromagnetic thin films with parallel surface magnetizations, expanding potential material applications.

Contribution

It introduces a criterion for the quantum anomalous Hall effect in magnetic topological insulator thin films regardless of interior magnetization configurations.

Findings

Quantum anomalous Hall effect occurs with parallel surface magnetizations.

Collinear antiferromagnetic structures can exhibit the effect without net magnetization.

Strategies for experimental realization of these states are discussed.

Abstract

We show that the quantum anomalous Hall effect almost always occurs in magnetic topological insulator thin films whenever the top and bottom surface layer magnetizations are parallel, independent of the interior layer magnetization configuration. Using this criteria we identify structures that have a quantum anomalous Hall effect even though they have collinear magnetic structures with no net magnetization, and discuss strategies for realizing these interesting magnetic states experimentally.