SrRuO3 heterostructures grown in the (111) direction are a rare example of thin film ferromagnets. By means of density functional theory plus dynamical mean field theory we show that the half-metallic ferromagnetic state with an ordered magnetic moment of 2μB/Ru survives the ultimate dimensional confinement down to a bilayer, even at elevated temperatures of 500K. In the minority channel, the spin-orbit coupling opens a gap at the linear band crossing corresponding to 43 filling of the t2g shell. We demonstrate that the respective state is Haldane's quantum anomalous Hall state with Chern number C=1, without an external magnetic field or magnetic impurities.
@article{arxiv.1610.01948,
title = {Quantum Anomalous Hall State in Ferromagnetic SrRuO$_3$ (111) Bilayers},
author = {Liang Si and Oleg Janson and Gang Li and Zhicheng Zhong and Zhaoliang Liao and Gertjan Koster and Karsten Held},
journal= {arXiv preprint arXiv:1610.01948},
year = {2017}
}