Length dependent properties of SNS microbridges

Using an in-situ, self-aligned deposition scheme, arrays of variable length SNS junctions in the range of 0.05μm to 1 μm have been fabricated. Arrays of SNS microbridges of lead-copper and niobium-copper fabricated using this technique have been used to study the length dependence, at constant temperature, of the critical current Icand bridge resistance Rd. For bridges with lengths L greater than the normal metal coherence length (T), the dependence of Icon L is consistent with an exponential dependence on the reduced length (T). For shorter bridges, deviations from this behavior is seen. It was also found that the bridge resistance Rddoes not vary linearly with the geometric bridge length but appears to approach a finite value as .