Phonon-induced topological phase transition in SnTe*

Unlike the topologically trivial semiconductor PbTe, SnTe has an inverted band gap at the L point that gives rise to a topological crystalline insulating phase protected by mirror symmetry [1]. In this work, we calculate the temperature renormalization of the electronic band structure of SnTe. We account for the energy shift of the electronic states due to thermal expansion, and electron-phonon interaction using the nonadiabatic Allen-Heine-Cardona formalism within density functional perturbation theory [2,3]. Corrections to the electronic band structure due to electron-electron interaction are obtained using many-body perturbation theory (GW). We capture the decrease of the direct gap with temperature yielding a temperature-induced phase transition to a topologically trivial phase at ~800 K. We find that both thermal expansion and electron-phonon interaction have a considerable effect on these temperature variations. We also analyze the temperature dependence of the electron-phonon self-energy.

[1] T. H. Hsieh et al., Nat. Commun. 3, 982 (2012)
[2] S. Ponce et al, J. Chem. Phys. 143, 102813 (2015)
[3] J. D. Querales-Flores et al, Phys. Rev. Mater. 3, 055405 (2019)