Josephson sandwiches with bismuth interlayer

A study was made of SNS-type Josephson sandwiches with a bismuth interlayer. The coherence length in thin bismuth films was measured and found to be equal to 30 +- 10 nm, much smaller than previous estimates. It is demonstrated that, with the correct selection of materials for the superconducting electrodes, one can obtain Josephson junctions with a characteristic voltage of the order of 1 mV and a normal resistance of the order 1 ohm having an area of 1 μ2