Interacting-bath dynamical embedding for capturing non-local electron correlation in solids

TL;DR

This paper introduces an ab initio Green's function embedding method with an interacting bath, combining coupled-cluster and GW theories to accurately capture local and non-local electron correlations in solids.

Contribution

It presents a new systematic and computationally efficient embedding approach that incorporates two-particle interactions in the bath, improving upon traditional dynamical mean-field theory.

Findings

GW+ibDET agrees well with experimental spectra across various materials

The method quantifies non-local electron correlation effects in solids

Addresses the bandwidth narrowing debate in metallic sodium

Abstract

Quantitative simulation of electronic structure of solids requires treating local and non-local electron correlations on an equal footing. We present a new ab initio formulation of Green's function embedding which, unlike dynamical mean-field theory that uses non-interacting bath, derives bath representation with general two-particle interactions in a systematically improvable manner. The resulting interacting-bath dynamical embedding theory (ibDET) utilizes an efficient real-axis coupled-cluster solver to compute the self-energy, approaching the full system limit at much reduced cost. When combined with the GW theory, GW+ibDET achieves good agreement with experimental spectral properties across a range of semiconducting, insulating and metallic materials. Our approach also enables quantifying the role of non-local electron correlation in determining material properties and addressing the long-standing debate on the bandwidth narrowing of metallic sodium.