Resistive Domains in Thin Superconducting Film Structures

Resistive domains in the thin superconducting films deposited on wide substrates are analyzed in the frame of a stepwise voltage-current characteristic of superconductors. The approach allows us to obtain analytical solutions of the two-dimensional heat-diffusion equation, to analyze the influence of the film shape on the domain properties, and to reveal the main distinctions in the properties of domains in superconducting wires and films. It was shown that the appearance of a domain in the film of complicated shape (e.g., meander) can cause the origination of other domains. The domain length can be an ambiguous function of a current and depends on the film shape. It is shown that due to the heat transfer through a substrate, the properties of domains in thin films significantly differ from the properties of domains in superconducting wires. The obtained results can be used at a design of the electronic and electrical devices based on superconducting films.