Ab initio study of Z(2) topological phases in perovskite (111) (SrTiO3)(7)/(SrIrO3)(2) and (KTaO3)(7)/(KPtO3)(2) multilayers

作者：Lado J L^*; Pardo V; Baldomir D

来源：Physical Review B, 2013, 88(15): 155119.

DOI：10.1103/PhysRevB.88.155119

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

• 出版日期2013-10-18