MERCURY-BASED SUPERCONDUCTORS WITH QUASI-NORMAL OCCUPANCY

A model with anomalous occupancy is applied to Hg-based cuprate superc onductors. The anomaly consists of a small energy gap near the Fermi s urface, the scale of the gap anomaly is of order of the cutoff (v.g. D ebye) energy. Values of the anomalous occupancy parameters for Hg-base d superconductors are obtained for different values of the ratio R and the effective coupling constant, within the weak coupling. As these m aterials have the highest transition temperature known for layered cop per-oxide superconductors, they serve as a new testing ground for vari ous proposed models.