Self-consistent ladder D$\Gamma$A approach

TL;DR

This paper introduces a self-consistent DΓA method for multi-orbital and ab initio models, demonstrating its effects on critical temperatures and non-local correlations in various Hubbard models and SrVO3.

Contribution

The paper develops and applies a self-consistent DΓA approach, improving upon previous methods by including feedback effects in multi-orbital and real-material calculations.

Findings

Self-energy feedback lowers critical temperatures, even to zero in 2D.

Non-local correlations are reduced with self-consistency, especially when strong.

One-shot calculations are adequate for weak to moderate non-local correlations, as in SrVO3.

Abstract

We present and implement a self-consistent D$\Gamma$A approach for multi-orbital models and ab initio materials calculations. It is applied to the one-band Hubbard model at various interaction strengths with and without doping, to the two-band Hubbard model with two largely different bandwidths, and to SrVO$_3$. The self-energy feedback reduces critical temperatures compared to dynamical mean-field theory, even to zero temperature in two-dimensions. Compared to a one-shot, non-self-consistent calculation the non-local correlations are significantly reduced when they are strong. In case non-local correlations are weak to moderate as for SrVO$_3$, one-shot calculations are sufficient.