Interplay of electron-phonon interaction and strong correlations: DMFT+\Sigma study

TL;DR

This paper investigates how electron-phonon interactions and strong electronic correlations influence the electronic properties of the Hubbard model, revealing the interplay between electronic and phononic kinks in energy spectra using an advanced DMFT+ extSigma approach.

Contribution

It introduces a combined DMFT+ extSigma method to study electron-phonon effects in strongly correlated systems, providing new insights into spectral features and kinks.

Findings

Identification of electronic and phononic kinks in spectra

Analysis of the interplay between electron-electron and electron-phonon interactions

Results for densities of states under various model parameters

Abstract

We perform investigation of Hubbard model with interaction between strongly correlated conducting electrons on a lattice with Debye phonons. To solve the problem generalized dynamical mean-field DMFT+\Sigma method is employed with "external" self-energy \Sigma_ph corresponding to electron-phonon interaction. We present DMFT+\Sigma_ph results for densities of states and kinks in energy dispersions for a variety of model parameters, analyzing the interplay of recently discovered kinks of purely electronic nature and usual phonon kinks in the electronic spectrum.