Current-Voltage Characteristics of Randomly Pinned Type II Superconductors

Abstract

An analytic expression is derived for the current-voltage characteristic of superconducting foils with dilute pins. For a randomly pinned superconductor, the dynamic critical current estimated in the flux flow state is of a comparable order as the static critical current, which has a close connection with the threshold criterion proposed by Labusch. The current vs voltage curve has a slightly concave tail and shows a sensitive dependence on the detailed shape of the pinning potential.