Transport processes and reduction of IcRn product in YBaCuO/PrBaCuO/YBaCuO ramp-type Josephson junctions

The mechanisms of current passage and the causes of IcRn (critical-current normal-resistance) product reduction of YBCO/PBCO/YBCO ramp-type junctions are analyzed. At PBCO (PrBa2Cu3Ox ) barrier thicknesses L=8-20 nm the junction characteristics are determined by the thickness of the PBCO barrier and its nature. The boundary resistance and depression of the YBCO (YBa2Cu3Ox) superconducting parameters near the interface do not strongly affect the junction parameters. The behaviour of the YBCO/PBCO/YBCO junctions cannot be described by simple SNS (superconductor-normal metal-superconductor) weak-link or SIS (superconductor-insulator-superconductor) tunnel models. A strong pair-breaking effect and a one-center inelastic tunneling process are taken into account to explain the Josephson and normal state characteristics of these junction