Correlated electrons in a crystalline topological insulator

We study the effects of electron-electron interaction in a three-dimensional crystalline topological insulator by adding on-site repulsion to the single-particle Hamiltonian and solving the many-body problem within cluster perturbation theory. The goal is to clarify how many-body effects modify the topological phase that stems from the crystal symmetries. Tuning the strength of the on-site interaction, we show that band inversion disappears in the bulk and surface states lose their metallic character.