Theory of Electronic Raman Scattering in Disordered $d-$wave Superconductors

TL;DR

This paper develops a theoretical framework for understanding how impurity scattering affects electronic Raman spectra in unconventional superconductors, aiding in distinguishing between different pairing symmetries.

Contribution

It provides a comprehensive theory linking impurity effects to Raman spectra in d-wave superconductors, matching experimental data on cuprates.

Findings

Impurity dependence helps differentiate between s-wave and d-wave gaps.

The theory accurately reproduces experimental Raman spectra for cuprates.

Inelastic scattering from spin fluctuations influences spectral features.

Abstract

A theory for the effect of impurity scattering on electronic Raman scattering in unconventional superconductors is presented. The impurity dependence of the the spectra can be used to to distinguish between conventional (anisotropic $s-$wave) or unconventional ($d$-wave) energy gaps, and excellent agreement with the data on three cuprate superconductors is shown for $d_{x^{2}-y^{2}}$ pairing. The full frequency dependence of the spectra can be reproduced by including inelastic scattering due to spin fluctuations and/or Coulomb scattering on a partially nested Fermi surface.