Cross-type submicron Josephson junctions using SNS technology for Josephson voltage standard applications

摘要

We have developed a very simple method for manufacturing submicrometer Josephson junctions (JJs) based on niobium and titanium layers. Together with the use of a microwave circuit consisting of modified coplanar strips this type of JJs offers the possibility of easy integration of several thousand submicrometer junctions in a microwave circuit. Up to this point we have manufactured and successfully tested arrays with 2000 super-ormal-/super-conductor junctions with areas from 0.3 μm×0.3 μm to 2.0 μm×2.0 μm. First measurements with microwave irradiation showed stable Shapiro steps at voltages up to 40 mV and, thereby, the proper operation of all 2,000 junctions was seen.