Normal reflection effect on the critical current in a clean-limit superconductor-normal-metal-superconductor junction

Abstract

Based on a simple matrix method, we investigate the effects of Fermi vector mismatch and elastic barrier on the dc Josephoson current through a ballistic, normal, one-dimensional quantum channel in contact with two superconducting electrodes. The coexistence of Andreev reflection and normal reflection forms quasi-bound states with open gaps in the normal conductor. The quantum transmission of individual electrons (or holes) gives new features to this mesoscopic system. The critical current character of a 2DEG coupled superconducting heterostructure with a length of sevral ξ 0 is extensively studied. More importantly, our theoritical results are able to account for the recent anomalous experimental results. © Springer-Verlag 1996.