QSGW+DMFT: an electronic structure scheme for the iron pnictides and beyond

TL;DR

This paper presents a combined QSGW+DMFT scheme to accurately describe the electronic structure of iron pnictides, capturing both local and non-local correlations, demonstrated through application to BaFe2As2.

Contribution

The paper introduces and details the implementation of the QSGW+DMFT method for iron-based superconductors, addressing the need to include both local and non-local electronic correlations.

Findings

QSGW+DMFT effectively models iron pnictides.

Dynamical and non-local correlations separate within the quasi-particle bandwidth.

Application to BaFe2As2 demonstrates the method's capabilities.

Abstract

While in strongly correlated materials one often focuses on local electronic correlations, the influence of non-local exchange and correlation effects beyond band-theory can be pertinent in systems with more extended orbitals. Thus in many compounds an adequate theoretical description requires the joint treatment of local and non-local self-energies. Here, I will argue that this is the case for the iron pnictide and chalcogenide superconductors. As an approach to tackle their electronic structure, I will detail the implementation of the recently proposed scheme that combines the quasi-particle self-consistent GW approach with dynamical mean-field theory: QSGW+DMFT. I will showcase the possibilities of QSGW+DMFT with an application on BaFe2As2. Further, I will discuss the empirical finding that in pnictides dynamical and non-local correlation effects separate within the quasi-particle band-width.