Published online by Cambridge University Press: 08 November 2006
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 ∝ (T c * − T)1/2 at low temperatures and J c ∝ (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.