THE LAYERED S-N MODEL OF HTSC AND ITS PHYSICAL-PROPERTIES

The superconductor is supposed to consist of alternating layers of two kinds: (1) layers with an attractive electron interaction and an effective mass of usual magnitude; (2) layers without interaction and with a large effective mass. The overlap between the layers is assumed to be small, its energy t being much less than DELTA. It is shown that such a model explains the most peculiar property found in experiments on electronic Raman light scattering: different threshold values for the Raman satellite measured at two different polarizations of the incident and scattered light. The tunnelling conductance G(V) = dJ/dV is analyzed for the same model. In order to fit the qualitative features of experimental data, it is assumed that the tunneling probability to the normal layers is much smaller than that to the superconducting layers. The conductance is calculated for the case t much less than DELTA. A brief analysis is given for the case t congruent-to DELTA, which proves that such an assumption definitely contradicts the experimental data for BSCCO. The possible nature of the electronic states in the normal layers is discussed.