ALL-HIGH-T-C SUPERCONDUCTOR RAPID-SINGLE-FLUX-QUANTUM CIRCUIT OPERATING AT SIMILAR-TO-30 K

We have implemented a simple circuit of the rapid single-flux-quantum (RSFQ) logic family using a single-layer YBa2Cu3O7-x thin-him structur e with 14 in-place Josephson junctions formed by direct electron beam writing. The circuit includes two dc/SFQ converters, two Josephson tra nsmission lines, a complete RS SFQ flip-flop, and an SFQ/dc converter (readout SQUID). Low-frequency testing has shown that the de-current-b iased circuit operates correctly and reliably at T similar to 30 K, a few degrees below the effective critical temperature of the junctions. Prospects for a further increase of the operation temperature and imp lementation of more complex RSFQ circuits are discussed in brief. (C) 1995 American Institute of Physics.