Overdamped $Nb∕Al–AlOx∕Nb$ Josephson junctions Available to Purchase

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 $JC$ from $103$ up to $2×104A∕cm2$⁠, with characteristic voltages from 80 to nearly $450μV$⁠. The junctions are stable against time and repeated thermal cycling.