We investigate the correlation-induced Mott, magnetic, and topological phase transitions in artificial (111) bilayers of perovskite transition-metal oxides LaAuO3 and SrIrO3 for which the previous density-functional theory calculations predicted topological insulating states. Using the dynamical-mean-field theory with realistic band structures and Coulomb interactions, LaAuO3 bilayer is shown to be far away from a Mott insulating regime, and a topological-insulating state is robust. On the other hand, SrIrO3 bilayer is on the verge of an orbital-selective topological Mott transition and turns to a trivial insulator by an antiferromagnetic ordering. Oxide bilayers thus provide a novel class of topological materials for which the interplay between the spin-orbit coupling and electron-electron interactions is a fundamental ingredient.
@article{arxiv.1401.0009,
title = {Correlation effects in (111) bilayers of perovskite transition-metal oxides},
author = {Satoshi Okamoto and Wenguang Zhu and Yusuke Nomura and Ryotaro Arita and Di Xiao and Naoto Nagaosa},
journal= {arXiv preprint arXiv:1401.0009},
year = {2015}
}