Superconductivity of Thin Metallic Films

The BCS approach to superconductivity of bulk structures was tested for a thin metallic film. The main difference between the bulk and the film lies in the fact that two electron zones and consequently two types of Couper's pairs appear in film. The pairing of electrons of one zone gives several times higher critical temperature with respect to the critical temperature of the bulk, while the pairing of electrons of the second zone gives superconductivity temperatures less than one Kelvin. The spatial splitting of two electron zones can be achieved by means of magnetic and electrical fields and this splitting offers the possibility to use only the current with higher critical temperature.