Size effects in Pb-alloy Josephson junctions

Five Pb-alloy Josephson junctions of various sizes were fabricated together and variations in their electrical parameters were studied. The dependence of the excess current on the junction geometric dimensions is demonstrated. As the area to perimeter ratio of the junction is increased, there is a proportional decrease in excess current density. A simple analysis indicates that there is an insignificant contribution to excess current through the interior planar area of the junction with most of the excess current generated at the edges.