CURRENT-INDUCED RESISTIVE STATES IN SUPERCONDUCTING FILMS

We present an experimental study of the current induced destruction of superconductivity in cylindrical indium films. The most interesting aspect of these experiments is the possibility to observe and investigate different mechanisms of the superconductivity destruction depending on the ratio of the sample thickness d to the coherence length xi(T). If d/xi(T)<4.5 we observe, above a critical current value, a resistive state throughout the section of the film, but in the case of d/xi(T)>4.5 the destruction of superconductivity starts, as in bulk samples, with the formation of a normal shell along the outer surface of the cylindrical sample together with a thin layer of the two-dimensional mixed state at the inner surface.