Nb/Al/AlOx/Al/AlOx/Al/Nb junctions with critical current densities, jc, up to 38kA/cm2 were fabricated. A critical voltage of Vc=1.25mV and small hysteresis (about 6% of the critical current) at 4.2 K were obtained for jc=21kA/cm2. Also, Nb/Al/AlOx/Al/Nb/Al/NbN junctions with jc=33kA/ cm2 and Vc=0.76mV were fabricated, where it is suggested that a second tunnel barrier at the Al/NbN interface is present as a result of Al nitridation during NbN deposition.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)