Electronic Polarons, Cumulants and Doubly Dynamical Mean Field Theory: Theoretical Spectroscopy for Correlated and Less Correlated Materials

TL;DR

This paper reviews advanced theoretical spectroscopy methods incorporating dynamical Coulomb interactions, focusing on dynamical mean field theory and its variants, to better understand correlated and less correlated materials like SrVO3.

Contribution

It introduces and discusses the development of doubly dynamical mean field theory and its relation to GW+DMFT and cumulant schemes for improved spectral analysis.

Findings

Demonstrates plasmonic satellite structures in SrVO3 spectra

Highlights the role of dynamical interactions in electronic structure

Connects theoretical methods to experimental spectral features

Abstract

The use of effective local Coulomb interactions that are dynamical, that is, frequency-dependent, is an efficient tool to describe the effect of long-range Coulomb interactions and screening thereof in solids. The dynamical character of the interaction introduces the coupling to screening degrees of freedom such as plasmons or particle-hole excitations into the many-body description. We summarize recent progress using these concepts, putting emphasis on dynamical mean field theory (DMFT) calculations with dynamical interactions ("doubly dynamical mean field theory"). We discuss the relation to the combined GW+DMFT method and its simplified version "Screened Exchange DMFT", as well as the cumulant schemes of many-body perturbation theory. On the example of the simple transition metal SrVO3, we illustrate the mechanism of the appearance of plasmonic satellite structures in the spectral properties, and discuss implications for the low-energy electronic structure.