Nucleation and growth of the superconducting phase in the presence of a current

Article

关键词: ASYMPTOTIC ANALYSIS;    SURFACE-TENSION;    DYNAMICS;    MODEL;   

DOI  :  10.1103/PhysRevB.57.5432

来源: SCIE

【 摘 要 】

We study the localized stationary solutions of the one-dimensional time-dependent Ginzburg-Landau equations in the presence of a current. These threshold perturbations separate undercritical perturbations which return to the normal phase from overcritical perturbations which lead to the superconducting phase. Careful numerical work in the small-current limit shows that the amplitude of these solutions is exponentially small in the current; we provide an approximate analysis which captures this behavior. As the current is increased toward the stall current J*, the width of these solutions diverges, resulting in widely separated normal-superconducting interfaces. We map out numerically the dependence of J* on u (a parameter characterizing the material) and use asymptotic analysis to derive the behaviors for large u (J*similar to u(-1/4)) and small u (J --> J(c), the critical depairing current), which agree: with the numerical work in these regimes. For currents other than J* the interface moves, and in this case we study the interface velocity as a function of u and J. We find that the velocities are bounded both as J --> 0 and as J --> J(c), contrary to previous claims.

【 授权许可】

Free