Josephson single‐flux‐quantum logic circuits using niobium weak links

Josephson logic circuits using fluxoid quantization in a one‐junction interferometer to represent logical states have been fabricated from thin films of Nb by means of photolithography, electron beam lithography, and reactive ion etching. A variable thickness bridge is used as a Josephson junction in the one‐junction interferometer. The logic circuits have shown AND and OR logic functions.