Interaction induced topological phase transition in Bernevig-Hughes-Zhang model

TL;DR

This paper investigates how electron interactions can induce topological phase transitions in the Bernevig-Hughes-Zhang model, using Green's functions and edge spectra to characterize the topological nature.

Contribution

It introduces a method to determine the Z2 topological index in interacting systems directly from Green's functions, aiding the search for correlated topological insulators.

Findings

Interaction can induce topological phase transitions.

The Z2 index is reliably calculated from Green's functions.

Method is compatible with ab initio approaches.

Abstract

We study interaction induced topological phase transition in Bernevig-Hughes-Zhang model. Topological nature of the phase transition is revealed by directly calculating the Z2 index of the interacting system from the single-particle Green's function. The interacting Z2 index is also consistently checked through the edge spectra. Combined with ab initio methods, present approach is a useful tool searching for correlated topological insulating materials from the first-principle point of view.