A latching-type driver circuit using capacitively-shunted HTS ramp-edge-type junctions

We developed a latching-type driver using capacitively shunted high-tempera ture superconductivity (HTS) junctions for Single-Flux-Quantum (SFQ)-semico nductor output interfaces and fabricated it using ramp-edge-type HTS juncti ons. Assuming a junction IcRn product of 2 mV, a circuit simulation shows t hat the driver can produce an output of about 8 mV from an SFQ input pulse with a sufficiently short rise time for an interface clock operation of sev eral gigahertz HTS junctions were fabricated using the interface engineerin g method, and capacitors were made from an Indium oxide insulator (the diel ectric constant was a bout 23 at 20 K) sandwiched by krBa(2)Cu(3)O(7-X) (YB CO) electrodes. The hysteresis of the I-V characteristics of the junctions increased by increasing the area of capacitance. The latching operation of the driver was observed with an output voltage of up to 3 mV.