Development and investigation of Nb-Al-oxide-Nb Josephson junction arrays [voltage standard application]

An array of 3072 Josephson junctions Nb-AlO/sub x/-Nb is developed at IEM "KVARZ". Some preliminary results of an investigation of I-V curves under microwave irradiation in the 70 GHz frequency band are given. Zero current quantized voltage steps are displayed up to 450 mV with an amplitude >100 /spl mu/A. An improvement of the fabrication process, which is in progress, will enable to increase quantized voltage steps region up to 1 V.<
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