Topological Nontrivial Phase in Hexagonal Antiperovskites A3BiB (A=Ba,Sr; B=P,N)

TL;DR

This paper predicts and verifies the existence of topological non-trivial phases in hexagonal antiperovskite compounds under pressure, using advanced calculations to analyze their electronic structure, stability, and spin textures.

Contribution

It introduces a new class of hexagonal antiperovskite materials exhibiting topological phases, supported by detailed computational analysis and topological invariant calculations.

Findings

Topological non-trivial phases are predicted in A3BiB compounds under pressure.

Surface dispersion and Z2 index confirm non-trivial topology.

Compounds are chemically and mechanically stable.

Abstract

In this article, we predict the occurrence of topological non-trivial phase in hexagonal antiperovskite systems. By carefully investigating the evolution of band structure, we have studied the pressure induced topological phase transition in Ba$_{3}$BiP, Ba$_{3}$BiN, and Sr$_{3}$BiN compounds using the hybrid functional calculations. The non-trivial topology has been verified by computing Dirac like surface dispersion and topological invariant {\it Z$_2$} index via parity analysis. The unconventional spin texture has been analyzed which guaranteed the absence of impurity induced backscattering on boundary of the sample while respecting the time reversal symmetry. Our simulation confirms the chemical and mechanical stability of all the three compounds. The present study introduces an important new class of hexagonal antiperovskite compounds in the topological regime and are believed to capture ample of attention both from theoretical as well as experimental front.