An experimental implementation of high-T_c-based RSFQ set-reset trigger at 4.2 K

A rapid single-flux quantum (RSFQ) set-reset trigger circuit has been implemented using YBaCuO grain boundary junctions on an asymmetric 32 degrees Y-ZrO₂ bicrystal. The circuit contains 18 Josephson junctions aligned along the grain boundary and required six film layers: a YBaCuO base electrode, two amorphous SrTiO₃ insulating layers, a superconducting Pb/Au/Cr ground plane and Au/Cr wiring. It consists of two DC-to-SFQ converters, two Josephson transmission lines and an SFQ-to-DC converter. Two pulse trains, 'signal' and 'clock', were applied to change the state of the trigger from '0' to '1' and vice versa, and registered at the SFQ-to-DC: output. All experiments were performed at 4.2 K.