INVERTER

PURPOSE:To realize an inverter which is free from malfunction without requiring complicated circuit constitution at all, by constituting one quantum interference gate by using at least two microbridge type elements which do not execute a latching operation, instead of a conventional tunnel type Josephson element. CONSTITUTION:As for inductances L1, L2 for connecting mutually two microbridge junctions J1, J2 which can make a Josephson current flow, its magnitude is L/2, and a quantum interferometer 1 is constituted of these inductances L1, L2 and microbridge junctions J1, J2. A bias magnetic field current IC is made to flow to a circuit, a threshold characteristic is moved in parallel to an input current IA so that it becomes the smallest critical current when IA is zero, and also a larger bias current IBI than this critical current IBmax in case when the input current is zero, so that an output voltage is generated in a state of IA=0. In this state, when the input signal current IA of an amplitude of DELTAIA is made to flow, the output voltage becomes zero while this current is flowing.