Topologically nontrivial phase in the hexagonal antiperovskites A3BiB (A=Ba,Sr; B=P,N)

Abstract

In this paper, we predict the occurrence of topological nontrivial phase in hexagonal antiperovskite systems. By carefully investigating the evolution of band structure, we have studied the pressure induced topological phase transition in Ba3BiP, Ba3BiN, and Sr3BiN compounds using the hybrid functional calculations. The nontrivial topology has been verified by computing Dirac like surface dispersion and topological invariant Z2 index via parity analysis. The unconventional spin texture has been analyzed which guaranteed the absence of impurity induced backscattering on the boundary of the sample while respecting the time reversal symmetry. Our simulation confirms the chemical and mechanical stability of all three compounds. The present study introduces an important class of hexagonal antiperovskite compounds in the topological regime and are believed to capture ample attention from both the theoretical and experimental front. © 2018 American Physical Society.