We propose realizing the quantum anomalous Hall effect by proximity coupling graphene to an antiferromagnetic insulator that provides both broken time-reversal symmetry and spin-orbit coupling. We illustrate our idea by performing ab initio calculations for graphene adsorbed on the (111) surface of BiFeO3. In this case, we find that the proximity-induced exchange field in graphene is about 70 meV, and that a topologically nontrivial band gap is opened by Rashba spin-orbit coupling. The size of the gap depends on the separation between the graphene and the thin film substrate, which can be tuned experimentally by applying external pressure.
@article{arxiv.1501.04828,
title = {Quantum Anomalous Hall Effect in Graphene Proximity Coupled to an Antiferromagnetic Insulator},
author = {Zhenhua Qiao and Wei Ren and Hua Chen and L. Bellaiche and Zhenyu Zhang and A. H. MacDonald and Qian Niu},
journal= {arXiv preprint arXiv:1501.04828},
year = {2015}
}