Proximity Effect in Cuprate Based Superconductor-Normal Metal-Superconductor Junctions

摘要

We report the Josephson coupling between optimally doped superconducting La_(1.85)Sr_(0.15)CuO_4 through the normal metal barrier of La_(1.85)Sr_0._(15)Cu_(0.97)Co_(0.03)O_4(LSCCO). The critical current (I_c) across the junction exists even up to a barrier thickness of 50 nm. The barrier thickness dependence study of I_c yields a large coherence length in LSCCO of (15.2±1.4) nm at 5 K, which indicates the presence of giant proximity effect in such systems.