Chern and Z₂ topological insulating phases in perovskite-derived 4d and 5d oxide buckled honeycomb lattices.

ABSTRACT: Based on density functional theory calculations including a Coulomb repulsion parameter U, we explore the topological properties of (LaXO₃)₂/(LaAlO₃)₄ (111) with X = 4d and 5d cations. The metastable ferromagnetic phases of LaTcO₃ and LaPtO₃ with preserved P321 symmetry emerge as Chern insulators (CI) with C = 2 and 1 and band gaps of 41 and 38 meV at the lateral lattice constant of LaAlO₃, respectively. Berry curvatures, spin textures as well as edge states provide additional insight into the nature of the CI states. While for X = Tc the CI phase is further stabilized under tensile strain, for X = Pd and Pt a site disproportionation takes place when increasing the lateral lattice constant from a_LAO to

SUBMITTER: Koksal O 

PROVIDER: S-EPMC6872743 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature