Title :
Subgap characteristics of Nb/AlOx/Nb tunnel junctions with high critical current density
Author :
Maezawa, M. ; Aoyagi, M. ; Nakagawa, H. ; Kurosawa, I. ; Takada, S.
Author_Institution :
Electrotech. Lab., Ibaraki, Japan
fDate :
6/1/1995 12:00:00 AM
Abstract :
We have investigated subgap characteristics of Nb/AlOx/Nb tunnel junctions with high critical current density (high-J/sub c/). A good agreement of the experimental data with the solution of Werthamer´s equation clearly shows that steep current steps observed at odd submultiples of the gap voltage, which cannot be explained by multiparticle tunneling and/or multiple Andreev reflection, are mainly caused by Josephson self-coupling. Our experimental results suggest that Josephson self-coupling is important to high-J/sub c/ tunnel junctions.<>
Keywords :
Josephson effect; aluminium compounds; critical current density (superconductivity); niobium; superconductor-insulator-superconductor devices; type II superconductors; Josephson self-coupling; Nb-AlO-Nb; Werthamer´s equation; critical current density; gap voltage; high-J/sub c/ tunnel junctions; steep current steps; subgap characteristics; tunnel junctions; Critical current density; Current-voltage characteristics; Equations; Laboratories; Magnetic field measurement; Magnetic fields; Niobium; Reflection; Tunneling; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on