Stability limits in two-band superconductor rings

TL;DR

This paper investigates the stability and phase-slip phenomena in two-band superconducting rings, developing a semi-analytical method to determine critical flux and exploring novel soliton states with differing phase windings.

Contribution

It introduces a semi-analytical approach based on linear instability theory to determine critical flux in two-band superconductors, and predicts the existence of soliton states with different phase windings.

Findings

Critical flux depends on band parameters and temperature.

A semi-analytical method for phase-slip analysis is developed.

Existence of soliton states with different phase windings is demonstrated.

Abstract

This study explores transitions between states with different winding number in two-band superconducting rings. From the time-dependent Ginzburg-Landau (TDGL) equations for two-component superconductors, we apply linear instability theory and develop a semi-analytical method that provides the critical flux for phase-slip occurrence. The developed method was applied to investigate how the critical flux depends on physical properties, such as band parameters and temperature. Finally, we show the possible existence of a soliton state, in which the phase winding number is different in each condensate.