Towards temperature-induced topological phase transition in SnTe*

In this work, the temperature renormalization of the bulk band structure of a topological crystalline insulator, SnTe [1], is calculated from first principles [2], including the effect of thermal expansion on the electron-phonon self-energy. We show that thermal expansion and electron-phonon interaction tend to decrease the band gap and drive SnTe closer to the phase transition to a normal insulating phase, in contrast to electron-electron interaction. We find that the band gap renormalization due to electron-phonon interaction exhibits a nonlinear dependence on temperature as the material approaches the topological phase transition, while the lifetimes of the conduction band states near the band edge show a nonmonotonic behavior with temperature. Our results show that electron-phonon interaction in topological materials is considerably affected by the thermal variations of their bulk electronic states. These effects should have important implications on bulk electronic and thermoelectric transport in SnTe and other topological insulators.


[1] T. H. Hsieh et al., Nat. Commun. 3, 982 (2012).
[2] J. D. Querales-Flores, P. Aguado-Puente, D. Dangić et al., Phys. Rev. B 101, 235206 (2020).