Unusual mechanism of vortex viscosity generated by mixed normal modes in superconductors with broken time reversal symmetry

TL;DR

This paper reveals a novel vortex viscosity mechanism in multiband superconductors with broken time-reversal symmetry, caused by mixed superfluid modes inside vortex cores, especially near phase transitions.

Contribution

It introduces a new vortex viscosity mechanism arising from mixed superfluid modes in multiband superconductors with broken time-reversal symmetry, differing from conventional theories.

Findings

New vortex viscosity mechanism identified

Dominant near time-reversal symmetry breaking transition

Potential relevance for $Ba_{1-x}K_{x}Fe_2As_2$ superconductor

Abstract

We show that under certain conditions multiband superconductors with broken time-reversal symmetry have a new vortex viscosity-generating mechanism which is different from that in conventional superconductors. It appears due to the existence of mixed superfluid phase-density mode inside vortex core. This new contribution is dominant near the time reversal symmetry breaking phase transition. The results could be relevant for three band superconductor $Ba_{1-x}K_{x}Fe_2As_2$.