Flux quantization for a vortex in two-gap superconductor

TL;DR

This paper demonstrates that magnetic flux quantization in two-gap superconductors differs from previous predictions, with flux quantized in units related to the model's parameters, revealing new insights into vortex behavior.

Contribution

It corrects the theoretical understanding of flux quantization in two-gap superconductors, showing quantization units depend on system parameters rather than being fixed.

Findings

Flux quantized in units of 2π/g in SU(2) model

Flux quantized in units of 2πα/g in U(1) model

Parameter α depends on Cooper pair masses and concentrations

Abstract

Contrary to recent theoretical prediction, we show that the magnetic flux of a vortex in SU(2) model of two-gap superconductor is quantized in units of 2\pi/g, not 4 \pi/g. For the U(1) version of this model, the flux is quantized in units of 2 \pi\alpha/g where 0 < \alpha < 1. The parameter \alpha depends on the masses and concentrations of the Cooper pairs in the two condensates.