Universal distribution of transparencies in highly conductive Nb/AlO(x)/Nb junctions.
We report the observation of the universal distribution of transparencies, predicted by Schep and Bauer [Phys. Rev. Lett. 78, 3015 (1997)] for dirty sharp interfaces, in uniform Nb/AlO(x)/Nb junctions with high specific conductance (10(8) ohm(-1) cm(-2)). Experiments used the BCS density of states in superconducting niobium for transparency distribution probing. Experimental results for both the dc I-V curves at magnetic-field-suppressed supercurrent and the Josephson critical current in zero magnetic field coincide remarkably well with calculations based on the multimode theory of multiple Andreev reflections and the Schep-Bauer distribution.
Naveh
Y
Y
Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794-3800, USA.
Patel
V
V
Averin
D V
DV
Likharev
K K
KK
Lukens
J E
JE