Functional interpolation expansion for nonequilibrium correlated impurities

TL;DR

This paper introduces a functional interpolation method within the auxiliary master equation framework to efficiently solve nonequilibrium correlated impurity problems in DMFT, reducing computational costs while maintaining accuracy.

Contribution

The paper presents a novel interpolation-based approach that improves efficiency and accuracy in solving impurity problems in nonequilibrium DMFT.

Findings

Accurately captures equilibrium and photodoped states in Hubbard model

Reduces computational cost compared to traditional methods

Demonstrates effectiveness on Anderson and Hubbard impurity models

Abstract

We present a functional interpolation approach within the auxiliary master equation framework to efficiently and accurately solve correlated impurity problems in nonequilibrium dynamical mean-field theory (DMFT). By leveraging a near-exact auxiliary bath representation, the method estimates corrections via interpolation over a few bath realisations, significantly reducing computational cost and increasing accuracy. We illustrate the approach on the Anderson impurity model and on the Hubbard model within DMFT, capturing equilibrium and long-lived photodoped states.