Memory applications of Nb-Nb2O5-Pb(In) tunnel junctions

This paper describes the fabrication and testing of a two-junction Josephson device which can be used as a DRO memory cell for the investigation of the feasability of a random access memory. The cell was fabricated by means of a 10-layers thin film process with Nb-Nb2O5-Pb(In) tunnel junctions. Quasi-static and dynamic experiments have been performed on these devices and compared to computer simulations. The agreement seems to be fairly good. Memory capability has been proven by successive write and destructive read out cycles in the quasi-static mode (up to 10 MHz). Very high speed transitions from superconductive to normal state initiated by current pulses in the control line have been observed to the limit (25 ps) of the test apparatus.