Temperature effects in the band structure of topological insulators

TL;DR

This study investigates how temperature influences the electronic band structure of topological insulators, revealing significant band gap changes and potential phase transitions driven by thermal effects.

Contribution

It provides first-principles insights into temperature-induced band structure modifications and phase transitions in topological insulators, highlighting the roles of thermal expansion and electron-phonon interactions.

Findings

Band gap changes up to 0.3 eV at 600 K

Temperature drives materials towards the normal state

Topological phase transitions may occur near critical points

Abstract

We study the effects of temperature on the band structure of the Bi$_2$Se$_3$ family of topological insulators using first-principles methods. Increasing temperature drives these materials towards the normal state, with similar contributions from thermal expansion and from electron-phonon coupling. The band gap changes with temperature reach $0.3$ eV at $600$ K, of similar size to the changes caused by electron correlation. Our results suggest that temperature-induced topological phase transitions should be observable near critical points of other external parameters.