Dual-fermion approach to the Anderson-Hubbard model

TL;DR

This paper applies the dual fermion algorithm to the Anderson-Hubbard model, demonstrating improved accuracy over dynamical mean-field methods in capturing localization transitions and nonlocal correlations.

Contribution

It introduces the dual fermion approach to disordered interacting systems and compares its performance with established cluster methods in various dimensions.

Findings

Dual fermion approach improves upon dynamical mean-field results.

It accurately captures antiferromagnetic, Mott, and Anderson localization transitions.

The method enables calculation of hysteresis in double occupancy considering nonlocal correlations.

Abstract

We apply the recently developed dual fermion algorithm for disordered interacting systems to the Anderson-Hubbard model. This algorithm is compared with dynamical cluster approximation calculations for a one-dimensional system to establish the quality of the approximation in comparison with an established cluster method. We continue with a three-dimensional (3d) system and look at the antiferromagnetic, Mott and Anderson localization transitions. The dual fermion approach leads to quantitative as well as qualitative improvement of the dynamical mean-field results and it allows one to calculate the hysteresis in the double occupancy in 3d taking into account nonlocal correlations.