SUPERCONDUCTING PROPERTIES OF ATOMIC S/N AND S/S' SUPERSTRUCTURES

The thermodynamic properties of a superlattice with two different layers (S/N system, superconducting and normal layers; S/S' system, two different superconducting layers) in the elementary cell are considered. The temperature dependences of the order parameters are discussed. The density of electronic states on different layers in S/N and S/S' superlattices are calculated. As follows from our consideration, the energy corresponding to the density of states maxima may be much higher than the BCS-value of 1.76T(c). The connection of this result with tunneling spectra of high-T(c) superconductors is discussed.