Pressure induced topological quantum phase transition in Sb_2Se_3

TL;DR

This study predicts that applying hydrostatic pressure to Sb_2Se_3 causes a topological quantum phase transition from a conventional insulator to a topological insulator, confirmed by band structure and surface state calculations.

Contribution

First-principles calculations reveal a pressure-induced topological phase transition in Sb_2Se_3, identifying critical pressure and associated electronic structure changes.

Findings

Sb_2Se_3 becomes a topological insulator under pressure

Bulk energy gap closes and reopens with inverted bands

Dirac-like surface states emerge at critical pressure

Abstract

Based on the first-principles band structure calculations, we investigate the effects of hydrostatic pressure on the conventional insulator (CI) Sb_2Se_3 and predict that it undergoes a topological quantum phase transition from a CI to a nontrivial topological insulator at a critical pressure value. The pressure-induced topological quantum phase transition is confirmed by calculating the evolution of the bulk energy gap as a function of pressure, the inversion of energy band structure, and the Z_2 topological invariant, as well as the existence of the Dirac-like topological surface states. Our predictions can be tested by both spectroscopy and transport experiments.