Current-Induced Flow of Domains in the Intermediate State of a Superconductor

Abstract

Current-induced flow of superconducting domains similar to the flow of normal domains (flux flow) has been observed in the intermediate state. A theory (neglecting the Hall effect) is presented for the motion of domains in an intermediate state of arbitrary topology. Without pinning, the current in the normal regions is uniform and equal to ${J}_{0}$, the average current density. Domains move with velocity ${v}_{D}=\frac{c{J}_{0}}{\ensuremath{\sigma}{H}_{c}}$. Both results agree with those previously derived for flux flow. Introducing pinning gives agreement between the predicted and measured velocities.