Temperature dependence of critical currents of two-gap superconductors

¹ Department of Physics, Faculty of Science and Literature, Cumhuriyet University, 58140 Sivas, Turkey
² Department of Physics, Faculty of Sciences, Ankara University, 06100 Tandoğan, Ankara, Turkey and Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143, Azerbaijan

Corresponding author: hsahin@cumhuriyet.edu.tr

Received: 9 February 2006
Revised: 30 May 2006
Accepted: 30 August 2006
Published online: 8 November 2006

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 ∝ (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.