Pseudo-gap and vertex correction of electron-phonon interaction

TL;DR

This paper uses Eliashberg theory with vertex corrections to explore how electron-phonon interactions influence superconductivity and pseudo-gap phenomena, revealing complex crossover behaviors and explaining doping-dependent Tc in cuprates.

Contribution

It introduces a detailed analysis of vertex corrections in strong-coupling superconductivity, providing new insights into the pseudo-gap and Tc variations in cuprates.

Findings

Vertex correction explains the pseudo-gap in cuprates.

Crossover behaviors occur from weak to strong coupling.

Tc maps show complex dependence on interaction parameters.

Abstract

The strong-coupling Eliashberg theory plus vertex correction is used to calculate the maps of transition temperature (Tc) in parameter-space characterizing superconductivity. Based on these Tc maps, complex crossover behaviors are found when electron-phonon interaction increases from weak-coupling region to strong-coupling region. The doping-dependent Tc of cuprate superconductors and most importantly the pseudo-gap can be explained as the effects of vertex correction.