Correlated electrons in a Crystalline Topological insulator

TL;DR

This paper investigates how electron-electron interactions influence the topological phases of a 3D Crystalline Topological Insulator, revealing that strong interactions can destroy band inversion and surface metallicity.

Contribution

It introduces a many-body analysis of electron interactions in a crystalline topological insulator using Cluster Perturbation Theory, highlighting interaction-driven topological phase modifications.

Findings

On-site repulsion destroys bulk band inversion.

Surface states lose metallic character with increasing interaction.

Electron correlations significantly alter topological properties.

Abstract

We study the effects of e-e interaction in a 3D 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 loose their metallic character.