Overdamped Nb/Al-AlOx/Nb Josephson junctions -: art. no. 042501

We report the fabrication and characterization of overdamped Nb/Al-AlOx/Nb superconductor-insulator-superconductor Josephson junction whose fabrication process derives from that of the well-known hysteretic junctions. These junctions are an intermediate state between the superconductor-normal metal-superconductor and the superconductor-insulator-superconductor Josephson junctions. Stable and reproducible nonhysteretic current-voltage characteristics are obtained with a proper choice of the fabrication parameters. We have measured critical current densities J(C) from 10(3) up to 2x10(4) A/cm(2), with characteristic voltages from 80 to nearly 450 muV. The junctions are stable against time and repeated thermal cycling. (C) 2005 American Institute of Physics.