Exact solution of the Ginzburg-Landau equation for the upper critical field of a dx2−y2 superconductor

Abstract

A dx2−y2 superconductor is modeled as the superconducting layers in the a−b plane, whose coupling in the c direction is approximated by the effective mass, within the Ginzburg-Landau theory. In this work, this model is applied to the system where the coherence length along the c direction is greater than the layer spacing. Based on our model, we calculate the upper critical field in a magnetic field lying in a−c plane and tilted by an angle from the c axis. According to our results, the curvature of Hc2(T) is upward, and the slope −dHc2(T)/dT depends on the angle between the c axis and the external field. The most interesting feature is that the ratio of the c-direction parameter related to the effective mass to the a−b plane parameter connected with the effective mass can influence Hc2. As the ratio is decreased, Hc2 becomes increased. We also find that there is no admixture of s-wave component in the critical regime and believe that the upward curvature of the Hc2(T) is the characteristic property of a d-wave superconductor.

Source-reported materials — not catalogue approval

Similar papers