We perform \textit{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 \textit{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 Z2 invariant calculation is performed to arrive at a holistic conclusion.
@article{arxiv.1712.02495,
title = {Bulk band inversion and surface Dirac cones in LaSb and LaBi : Prediction of a new topological heterostructure},
author = {Urmimala Dey and Monodeep Chakraborty and A. Taraphder and Sumanta Tewari},
journal= {arXiv preprint arXiv:1712.02495},
year = {2018}
}