Zero bias conductance peak enhancement in Bi2Sr2CaCu2O8/Pb tunneling junctions

Recently, there has been tremendous interest on a tunneling feature called zero bias conductance peak (ZBCP) commonly found in high T_csuperconductor tunnel junctions. The interest stemmed from the feature’s root in the d-wave symmetry of high T_csuperconductors. In this paper we will review results of our study on ZBCP within a Pb/Bi₂Sr₂CaCu₂O₈(BSCCO) tunneling junction. This allows us to investigate the intricate interactions between s- and d-wave superconductivity. The ZBCP indeed demonstrates interesting properties when Pb becomes superconducting. We attribute these results to the suppression of the d-wave phase on the surface of BSCCO by the s-wave superconductivity from Pb through a proximity effect. We will also report some recent results on the magnetic field dependence of the ZBCP.