In high-T/sub c/ superconductors, being layered, doped Mott insulators, in-plane weak links occur easily in preparation and in growth, and are prone to deteriorate further. CuO-plane weak links are the major obstacles for HTS transport currents, both dc and rf. Weak links are tunnel junctions showing reduced critical Josephson currents j/sub cJ/ (A/cm/sup 2/), enhanced normal R/sub bn/ (/spl Omega/cm/sup 2/) and leakage resistances R/sub bl/(T0.2 nm as tunnel barrier width of height /spl phi//spl ap/2 eV, and with n/sub L//spl ap/10/sup 21//cm/sup 3/ localized states causing R/sub bl//spl prop/1/n/sub L/. For the first time their R/sub bl/, j/sub cJRbn/ and j/sup 2//sub cJRbn/ degradations are quantified by the resonant tunnel model, even for interface engineered junctions (IEJ), in agreement with experimental data. Comparison of HTS junctions with Nb/Nb/sub 2/O/sub 5y/ and Nb/Al/AlO/sub x/(OH)/sub y/ junctions shows ways out of the interface chemistry deadlock.
No takes yet. Share an insight, caveat, or question.
J. Halbritter (2003) studied this question.