Superconducting non-destructive readout circuits
摘要
說明書
Single-read RQL D-register circuit 700 uses the phase of Joseph junction J2 in body stage 702 to encode a stored state value and to source a stable pre-critical bias current to Josephson junction J5 in tail stage 704. Although this pre-critical bias current is insufficient to cause Josephson junction J5 to trigger, it sufficiently biases Josephson junction J5 such that its triggering is directly correlated to the value of the non-destructive readout input signal NDRO. Specifically, a positive NDRO pulse will trigger Josephson junction J5 and thereby send out an SFQ pulse to output QO, and a negative NDRO pulse will reset Josephson junction J5. The bias from input NDRO can be made weak, and isolation between the tail stage 704 to the body stage 702 (i.e., in the tail-to-body direction) can be sufficiently high to avoid any corruption of the body-stored state by NDRO signals, which is what makes the readout “non-destructive.”
