On the Free Carrier-Negative U Center Interacting Model for the High- T _c Oxide Superconductor

Abstract

Using the free carrier-negative U center interacting model, we have investigated the superconducting transition^.temperature T c , the specific heat jump at T c , the coherence length, the penetration depth, the thermodynamic critical field and the isotope effect for the high-T c oxide superconductor. The theoretical values of these physical quantities are consistent with the experimental values. Further, the residual electronic specific heat in the superconducting state is explained as the result of the inherent instability in this superconductive mechanism.