Self-consistent ladder dynamical vertex approximation

Abstract

The dynamical vertex approximation and related methods represent a great leap forward in the description of nonlocal electronic correlations. It is based on a local two-particle irreducible vertex, from which the momentum-dependent self-energy is constructed via Bethe-Salpeter and Schwinger-Dyson equations. In this paper, the hitherto used one-shot calculations are improved by repeating these equations with feedback from the updated self-energy until self-consistency. The validity of the method is benchmarked by several numerical examples and, prominently, the formation of a pseudogap is demonstrated.