Stability of vortex in a two-component superconductor

TL;DR

This paper investigates the thermodynamic stability of composite vortices in two-component superconductors using Ginzburg-Landau theory, revealing stability conditions dependent on three key parameters and identifying stable vortex states in mixed-type materials.

Contribution

It introduces a stability criterion for vortices in two-component superconductors based on three dimensionless parameters, expanding understanding of vortex behavior in complex superconducting systems.

Findings

Vortex stability depends on three independent parameters: $\kappa_1$, $\kappa_2$, $\kappa_\xi$.

Stable vortices exist in certain parameter ranges for mixed-type superconductors.

The study provides conditions for thermodynamic stability of composite vortices.

Abstract

Thermodynamic stability of composite vortex in a two-component superconductor is investigated by the Ginzburg-Landau theory. The predicted nature of these vortices has recently attracted much attention. Here we consider axially symmetric quantized vortex and show that the stability of vortex depends on three independent dimensionless parameters: $\kappa _{1}$, $\kappa _{2}$, $\kappa _{\xi}$, where $\kappa _{i}(i=1,2)$ is the Ginzburg-Landau parameter of individual component, $\kappa _{\xi }=\xi _{1}/\xi _{2}$ is the ratio of two coherence lengths. We also show that there exists thermodynamic stable vortex in type-1+type-2 or type-2+type-2 materials over a range of these three parameters.