Ab initio study of Z 2 topological phases in perovskite (111) (SrTiO 3 ) 7 /(SrIrO 3 ) 2 and (KTaO 3 ) 7 /(KPtO 3 ) 2 multilayers

摘要: Honeycomb structures formed by the growth of perovskite 5d transition metal oxide heterostructures along (111) direction in a t(2g)(5) configuration can give rise to topological ground states characterized index nu = 1, as reported Xiao et al. [Nat. Commun. 2, 596 (2011)]. Using combination tight binding model and ab initio calculations we study multilayers (SrTiO3)(7)/(SrIrO3)(2) (KTaO3)(7)/(KPtO3)(2) function parity asymmetry, on-site interaction U, uniaxial strain determine nature evolution gap. According our density functional theory calculations, is found be semimetal whereas present insulating phase that understood high U limit previous one, driven trivial perpendicular external electric field.