Eliashberg-type equations for correlated superconductors

TL;DR

This paper derives Eliashberg-type equations for strongly correlated superconductors considering electron-phonon interactions and Coulomb effects, revealing anisotropic pairing symmetries and their dependence on carrier concentration.

Contribution

It introduces a novel derivation of anisotropic Eliashberg equations accounting for strong correlations and Coulomb interactions in superconductors.

Findings

d-wave pairing dominates at low hole doping

Coupling constants vary with carrier concentration

Equations accommodate s, p, and d wave symmetries

Abstract

The derivation of the Eliashberg -- type equations for a superconductor with strong correlations and electron--phonon interaction has been presented. The proper account of short range Coulomb interactions results in a strongly anisotropic equations. Possible symmetries of the order parameter include s, p and d wave. We found the carrier concentration dependence of the coupling constants corresponding to these symmetries. At low hole doping the d-wave component is the largest one.