Thermomagnetic instability and features of the dynamic response of superconducting films

Abstract

A simple model of magnetic flux dynamics in a superconducting film strip is proposed. The model combines the classical phenomenology of temperature-dependent pinning and vortex motion, on the one hand, and an exact expression for the current distribution in the film in terms of the distribution of vortex density, on the other, and the diffusion of vortices is also taken into account. The model clearly reveals the features of the evolution of magnetic flux in the film due to the plane two-dimensional geometry of the film and the corresponding features of the dynamic response of the film, and it finds agreement with experiments.