Topological Phases in Oxide Heterostructures with Light and Heavy Transition Metal Ions

摘要

Using a combination of density functional theory, tight-binding models, andHartree-Fock theory, we predict topological phases with and withouttime-reversal symmetry breaking in oxide heterostructures. We consider bothheterostructures containing light transition metal ions, and those containingheavy transition metal ions. We find the (111) growth direction naturally leadsto favorable conditions for topological phases in both perovskite structuresand pyrochlore structures. For the case of light transition metal elements,Hartree-Fock theory predicts the spin-orbit coupling is effectively enhanced byon-site multiple-orbital interactions and may drive the system through atopological phase transition, while heavy elements with intrinsically largespin-orbit coupling require much weaker, or even vanishing electroninteractions to bring about a topological phase.