A subnanosecond Josephson tunneling memory cell with nondestructive readout

摘要: The design and experimental investigation of a Josephson tunneling memory cell with nondestructive readout (NDRO) is described. consists relatively large (20/spl times/25 mil/SUP 2/) superconductive loop which contains two write gates. NDRO performed third gate per cell. It shown that such an L, R, C parallel circuit must be critically damped. Design equations are established ensure critical damping solely the single-particle resistance Current transfer time (cell switching time) was measured to /spl sime/600 ps. From consecutive cycles it estimated writing could repetition rate ges/1 GHz. No loss in circulating current detected after 5/spl times/10/SUP 8/ cycles. operating margins, without word, bit, sense disturbs, allowed independent variations plusmn/11.5 percent word current, plusmn/26 bit plusmn/15 current. These results show ultra high speed random access memories zero standby power can built devices. Smaller times expected miniaturized cells.