Interaction-Induced Quantum Anomalous Hall Phase in (111) Bilayer of LaCoO3

In the present paper, the Gutzwiller density functional theory (LDA+G) has been applied to study the bilayer system of LaCoO3 grown along the (111) direction on SrTiO3. The LDA calculations show that there are two nearly flat bands located at the top and bottom of eg bands of Co atoms with the Fermi level crossing the lower one. After including both the spin-orbit coupling and the Coulomb interaction in the LDA+G method, we find that the interplay between spin-orbit coupling and Coulomb interaction stabilizes a very robust ferromagnetic insulator phase with the nonzero Chern number indicating the possibility of realizing the quantum anomalous Hall effect in this system. © 2015 American Physical Society.