A Josephson dc-powered latch

A new dc-powered Josephson latch has been designed and experimentally investigated.A latch is defined as a digital circuit in which information can be stored in a controlled manner. The latch we describe here consists of a nonlatching interferometer in series with a superconducting storage loop containing a second interferometer. Within the nominal operating region the latch has only two stable states and it does not display the problem of falling into a stable faulty state, in which the latch would respond to neither of its inputs (SET or RESET). Computer simulations using nominal 2.5-μm technology-device models indicate that the latch changes state in about 80 ps.