Stability of vortex in a two-component superconductor

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), and 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 thermodynamically stable vortex in a two-component superconductor over a range of these three parameters.