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arXiv · 1712.02495

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

Urmimala Dey·Monodeep Chakraborty·A. Taraphder·Sumanta Tewari
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Abstract

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 $\mathbb{Z}_2$ invariant calculation is performed to arrive at a holistic conclusion.

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Urmimala Dey, Monodeep Chakraborty, A. Taraphder, Sumanta Tewari. 2017-12-07. Bulk band inversion and surface Dirac cones in LaSb and LaBi : Prediction of a new topological heterostructure. https://doi.org/10.1038/s41598-018-33273-6

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