McMillan-Rowell oscillations observed in c-axis Au/Bi2Sr2CaCu2O8+delta junctions

Abstract

We observed periodic oscillations in the differential resistance vs. voltage curves of Au/Bi2Sr2CaCu2O8+x (Au/Bi2212) junctions near the bulk superconducting transition temperature T, of the Bi2212 single crystals. The oscillations can be explained in terms of the McMillan-Rowell coherent states resulting from the Andreev-reflected quasiparticles in the normal-metallic layer. This is the first observation of the McMillan-Rowell oscillations in the c-axis transport of the Bi2212 material. (C) 2004 Elsevier B.V. All rights reserved.