Non-rigid hole band in the extended t-J model

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 quasibound 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 m0 is extensively studied. More importantly, our theoritical results are able to account for the recent anomalous experimental results.