A Josephson logic design employing current-switched junctions

A logic scheme using Josephson tunnel junctions in a current-steering mode is described. Switching from voltage
V = 0
to
V \neq 0
is accomplished by adding a fraction of the control-line currents to the bias current. In one form the addition is accomplished by shunting the junction to be switched with a loop containing a second junction serving a diode-like function and causing one or more control lines to possess inductive coupling to the loop. A five-element circuit demonstrating AND, OR and INVERSION operations carried out by this approach has been fabricated and works as expected.