Fabrication of HTS long-JTL circuits on La-YBCO ground plane

We have fabricated high-temperature superconducting (HTS) long Josephson transmission line (JTL) circuits based on a multilayer structure. The JTL is composed of La0.2-Y0.9Ba1.9Cu3O x(La-YBCO) ground plane and base-electrode layers, a La0.2-Yb0.9Ba1.9Cu3O x(La-YbBCO) counter-electrode layer, and SrSnO3 insulating layers. The long JTL circuit consists of a dc-SFQ converter, a 96-junction JTL, and a SFQ-dc converter. The circuit was fabricated in an area as wide as 1.6 mm. Bias current was supplied to the JTL of 96 junctions through six ports that were separated each other. An SFQ pulse generated by the dc-SFQ converter could be propagated through the long JTL circuit, and the output signal was read out by the SFQ-dc converter. Correct operation of the long JTL circuit has been successfully demonstrated at temperatures up to 38 K. We have examined the dc-bias margins of all bias currents up to a temperature of 35 K