A 512-bit shift register using compact two-phase single fluxquantum clock generators with large margins and low power

A 512-b shift register was built and tested up to 14.5 GHz. The shift register uses a two-phase clock which is generated by coupling a master control line over many asymmetrically biased two-junction SQUIDs. Compared with other shift registers with Josephson transmission lines to deliver clock, this new clock system provides short delay, low power dissipation, and large DC bias margins. The shift register uses about 3000 Nb/AlO_x/Nb Josephson junctions and consumes about 0.1 mW