In a heterostructure of graphene and the ferromagnetic insulator EuO, the Eu atoms induce proximity exchange and inter-valley interactions in the graphene layer. Constrained by the lattice symmetries, and guided by ab initio calculations, a model Hamiltonian is constructed that describes the low-energy bands. Band parameters such as proximity induced exchange splitting, spin orbit coupling, and inter-valley interaction are determined. Calculations of the Chern number identify the conditions under which the hetero-structures exhibit topologically non-trivial bands that give rise to the quantum anomalous Hall effect with a Hall conductivity of σxy=2e2/h.
@article{arxiv.1509.06427,
title = {Proximity induced quantum anomalous Hall effect in graphene/EuO hetero-structures},
author = {Shanshan Su and Yafis Barlas and Roger K. Lake},
journal= {arXiv preprint arXiv:1509.06427},
year = {2017}
}