Simplified topological invariants for interacting insulators

TL;DR

This paper introduces a unified method for characterizing topological phases in interacting insulators using zero-frequency Green's functions, enabling efficient analysis across various dimensions and types.

Contribution

It proposes general topological order parameters based on Green's functions at zero frequency, applicable to a wide range of interacting topological insulators.

Findings

Unified description of interacting topological insulators

Efficient evaluation using Green's functions at zero frequency

Applicable across multiple dimensions and insulator types

Abstract

We propose general topological order parameters for interacting insulators in terms of the Green's function at zero frequency. They provide an unified description of various interacting topological insulators including the quantum anomalous Hall insulators and the time reversal invariant insulators in four, three and two dimensions. Since only Green's function at zero frequency is used, these topological order parameters can be evaluated efficiently by most numerical and analytical algorithms for strongly interacting systems.