ZERO-BIAS ANOMALIES IN HIGH-TC-SUPERCONDUCTOR TUNNEL-JUNCTIONS

The zero-bias. conductance peak that is often found in the tunneling characteristics of high-temperature-superconductor (HTS) junctions is analyzed in the framework of the Anderson-Appelbaum model for electron magnetic interaction. We have found that when the anomaly develops at T > T(c), its temperature behavior is determined by the superconducting properties of the HTS, while, when it develops at T < T(c), the presence of normal or semiconducting surface regions can be supposed. A giant resistance peak seems to indicate interdiffusion of the counterelectrode into the base material.