Title :
Properties of high-jc SINIS junctions
Author :
Nevirkovets, I.P. ; Shafranjuk, S.E. ; Ketterson, J.B. ; Rudenko, E.M.
Author_Institution :
Dept. of Phys. & Astron., Northwestern Univ., Evanston, IL, USA
fDate :
6/1/2003 12:00:00 AM
Abstract :
Nb/Al/AlOx/Al/AlOx/Al/Nb junctions with high critical current densities, jc, above 20 kA/cm2 were fabricated and characterized. A critical voltage of Vc=1.25 mV and small hysteresis (about 6% of the critical current) at 4.2 K were obtained for jc=21 kA/cm2. Also, devices with a modified geometry, Nb/Al/AlOx/Al/Nb/Al/AlOx/Al/Nb, were fabricated. In these devices, jc≅50 kA/cm2 at 4.5 K, and the temperature dependence of the critical current, Ic(T), is improved (as compared with our earlier results) in that the steep raise of Ic is shifted toward higher temperatures. We suggest a theoretical model which satisfactory describes the enhanced critical current for these SINS´NIS junctions as compared with ordinary SINIS junctions.
Keywords :
Josephson effect; alumina; aluminium; critical current density (superconductivity); niobium; superconductor-insulator-superconductor devices; type II superconductors; 1.25 mV; 4.2 K; 4.5 K; Josephson effect; Nb-Al-AlOx-Al-AlOx-Al-Nb; Nb/Al/AlOx/Al/AlOx/Al/Nb junctions; critical voltage; high critical current densities; high-jc SINIS junctions; small hysteresis; Circuits; Critical current; Critical current density; Hysteresis; Josephson junctions; Niobium; Physics; Superconducting devices; Superconducting materials; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.814161
