Interplay of Fermi velocities and healing lengths in two-band superconductors

TL;DR

This study numerically investigates how differences in Fermi velocities influence the healing lengths of two-band superconductors, revealing their impact on vortex structures and length-scale regimes.

Contribution

It demonstrates that band Fermi velocities significantly affect the disparity and temperature dependence of condensate healing lengths in two-band superconductors.

Findings

Fermi velocities strongly influence healing length disparities.

Changing Fermi velocity ratios alters temperature dependence of condensate lengths.

Length-scale locking parameters are significantly shifted by Fermi velocity ratios.

Abstract

By numerically solving the Bogoliubov-de Gennes equations for the single vortex state in a two-band superconductor, we demonstrate that the disparity between the healing lengths of two contributing condensates is strongly affected by the band Fermi velocities, even in the presence of the magnetic field and far beyond the regime of nearly zero Josephson-like coupling between bands. Changing the ratio of the band Fermi velocities alters the temperature dependence of the condensate lengths and significantly shifts parameters of the ``length-scales locking" regime at which the two characteristic lengths approach one another.