Temperature dependence of critical currents of two-gap superconductors

Abstract

In this paper, we consider the two-gap Ginzburg-Landau (G-L) free energy functional including the interactions, and obtain a very simple and explicit formula which presents the relation between the critical current density and temperature. The result shows that the temperature dependence of critical current density of a two-gap superconductor is of the form J(c) proportional to (T-c*- T)(1/2) at low temperatures and J(c) proportional to (T-c* - T)(3/2) near the critical temperature. Our critical current density expression is in accord with the previous theoretical work and experimental data.