Josephson logic circuits based on nonlinear current injection in interferometer devices

Nonlinear current-injection switching of Josephson interferometer devices is achieved by current injection into an asymmetric feedpoint. This method of switching interferometers has two important features: higher gain than in previous approaches and a novel nonlinear threshold curve which is of practical interest. A new family of high-performance logic gates based on nonlinear current injection is described. Logic circuits have been experimentally tested and preliminary results are presented.