Self-consistent calculation of the flux-flow conductivity in diffusive superconductors

TL;DR

This paper uses the Keldysh-Usadel theory to accurately calculate flux-flow conductivity in diffusive superconductors, accounting for electron-phonon interactions and matching experimental data.

Contribution

It provides a self-consistent method to determine flux-flow conductivity across temperature regimes, incorporating inelastic relaxation effects for the first time.

Findings

Inelastic electron-phonon relaxation suppresses flux-flow conductivity significantly.

Exact dimensionless parameters for diffusion-controlled flux-flow conductivity are identified.

Theoretical results align well with experimental measurements.

Abstract

In the framework of Keldysh-Usadel kinetic theory, we study the temperature dependence of flux-flow conductivity (FFC) in diffusive superconductors. By using self-consistent vortex solutions we find the exact values of dimensionless parameters that determine the diffusion-controlled FFC both in the limit of the low temperatures and close to the critical one. Taking into account the electron-phonon scattering we study the transition between flux-flow regimes controlled either by the diffusion or the inelastic relaxation of non-equilibrium quasiparticles. We demonstrate that the inelastic electron-phonon relaxation leads to the strong suppression of FFC as compared to the previous estimates making it possible to obtain the numerical agreement with experimental results.