Bulk band inversion and surface Dirac cones in LaSb and LaBi: Prediction of a new topological heterostructure.

ABSTRACT: We perform ab initio investigations of the bulk and surface band structures of LaSb and LaBi and resolve the existing disagreements about the topological property of LaSb, considering LaBi as a reference. We examine the bulk band structure for band inversion, along with the stability of surface Dirac cones (if any) to time-reversal-preserving perturbations, as a strong diagnostic test for determining the topological character of LaSb, LaBi and LaSb-LaBi multilayer. A detailed ab initio investigation of a multilayer consisting of alternating unit cells of LaSb and LaBi shows the presence of band inversion in the bulk and a massless Dirac cone on the (001) surface, which remains stable under the influence of time-reversal-preserving perturbations, thus confirming the topologically non-trivial nature of the multilayer in which the electronic properties can be tailored as per requirement. A detailed [Formula: see text] invariant calculation is performed to arrive at a holistic conclusion.

SUBMITTER: Dey U 

PROVIDER: S-EPMC6173707 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature