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 at some temperature, independent of the interior layer magnetization configuration. Using this criterion, 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.

• Received 5 October 2021
• Revised 10 April 2022
• Accepted 16 November 2022

DOI:https://doi.org/10.1103/PhysRevB.106.195433