Vortex motion and flux-flow resistivity in dirty multiband superconductors

TL;DR

This paper investigates vortex motion and flux-flow resistivity in dirty multiband superconductors, revealing non-universal resistive behavior influenced by pairing constants and diffusivity ratios, with results aligning with experimental data for MgB₂.

Contribution

It provides a microscopic kinetic theory analysis of vortex lattice conductivity in multiband superconductors, highlighting the dependence on material-specific parameters.

Findings

Resistive properties depend on pairing constants and diffusivity ratios.

Low-field magneto-resistance can exceed Bardeen-Stephen estimates.

Results agree with experimental data for MgB₂.

Abstract

The conductivity of vortex lattices in multiband superconductors with high concentration of impurities is calculated based on microscopic kinetic theory. Both the limits of high and low fields are considered, when the magnetic induction is close to or much smaller than the critical field strength $H_{c2}$, respectively. It is shown that in contrast to single-band superconductors the resistive properties are not universal but depend on the pairing constants and ratios of diffusivities in different bands. The low-field magneto-resistance can strongly exceed Bardeen-Stephen estimation in a quantitative agreement with experimental data for two-band superconductor MgB$_2$.