Preparation and Characterization of Nb/MgO/Bi2Sr2CaCu2Ox Junctions Using the Cleavage Planes of a Single-Crystal Superconductor

Abstract
Nb/MgO/Bi-Sr-Ca-Cu-O junctions using the cleavage planes of Bi2Sr2CaCu2O x single crystals have been fabricated using an artificial barrier for the first time. A large step, in the order of several hundred nm on the cleavage plane, proved to be closely related to the anisotropic behavior of tunneling spectroscopy through the surface of a Bi2Sr2CaCu2O x single crystal. This effect for the results of quasi-particle tunneling in the Nb/MgO/Bi-Sr-Ca-Cu-O junctions was in good agreement with calculated results for the local density of states in the superconductor/normal-conductor superstructure model.