Interplay between electron-phonon and Coulomb interactions in cuprates

TL;DR

This paper reviews evidence of strong electron-phonon coupling in high-Tc cuprates and explores how Coulomb interactions influence spectral functions, polaron formation, and correlation effects in these materials.

Contribution

It provides a comprehensive analysis of the interplay between electron-phonon and Coulomb interactions in cuprates, highlighting their effects on spectral functions and polaron formation.

Findings

Phonon self-energy is strongly reduced in weakly doped cuprates due to correlations.

No significant reduction observed in electron self-energy from Coulomb effects.

Experimental indications of polarons are linked to strong electron-phonon interactions in undoped cuprates.

Abstract

Evidence for strong electron-phonon coupling in high-Tc cuprates is reviewed, with emphasis on the electron and phonon spectral functions. Effects due to the interplay between the Coulomb and electron-phonon interactions are studied. For weakly doped cuprates, the phonon self-energy is strongly reduced due to correlation effects, while there is no corresponding strong reduction for the electron self-energy. Polaron formation is studied, focusing on effects of Coulomb interaction and antiferromagnetic correlations. It is argued that experimental indications of polaron formation in undoped cuprates are due to a strong electron-phonon interaction for these systems.