1996/02/06 by F. Marsiglio, Marsiglio, F., J. P. Carbotte +2
Physics and Astronomy · #Condensed Matter (cond-mat) #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Superconductivity in MgB2 and Alloys #cond-mat
paper · pdf · doi:10.48550/arxiv.cond-mat/9602031
25 pages, for 16 Postscript figures please contact first Author
arxiv created 1996/02/06 · openalex publication_date 1996/02/06 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We compute the single particle inverse lifetime, evaluated in the superconducting state. Within the BCS framework, the calculation can be done non-perturbatively, i.e. poles can be found well away from the real axis. We find that perturbative calculations are in good agreement with these results, even for non-zero impurity scattering. With electron-phonon scattering added to the problem, we use the Eliashberg equations, with impurity scattering, to calculate the quasiparticle inverse lifetime perturbatively. In all cases we find that the inverse lifetime is significantly suppressed in the superconducting state, particularly in the presence of impurity scattering. We also compute the far-infrared and microwave conductivity, and describe procedures for extracting scattering rates from conductivity measurements. While these procedures lead to scattering rates in qualitative agreement with the inverse lifetime, we find that quantitative agreement is lacking, in general.