The tunneling cryotron—A superconductive logic element based on electron tunneling

This paper discusses the operation of a new superconductive logic element. In geometry, the element resembles the in-line cryotron and like the in-line cryotron exhibits gains of greater than unity when biased. The gate, however, is a Josephson junction. The two states, zero-voltage and "resistive," of the junaction are both superconducting states, one being a pair tunneling state, the other a single-particle tunneling state. The transition from one state to the other takes place in less than 800 ps (the resolving time of the apparatus). If used in a flip-flop circuit in a current steering mode, current transfer times are calculated to be less than 200 ps.