Abstract
The electronic Raman scattering by pairs of quasiparticles is calculated at zero temperature, generalizing previous calculations that were based on the Bardeen-Cooper-Schrieffer model of a super-conductor. Analytical and numerical results are presented for the spectrum as a function of wave vector , and an integration is performed over to include the effect of a finite optical penetration depth. Allowing for gap anisotropy, we correct the results for vertex and Coulomb polarization effects. The theoretical results for finite are used to calculate spectra for Sn, Si, and Nb, neglecting gap anisotropy. Experimental data are presented for Si and Nb. The data for Si are fit to a zero- theory that includes gap anisotropy, with results similar to those presented earlier for Sn. The role of possible excitons on the Raman spectra is examined. These theoretical results are then used to discuss the self-energy of a Raman-active optical phonon in a superconductor.
- Received 8 August 1983
DOI:https://doi.org/10.1103/PhysRevB.29.4976
©1984 American Physical Society