Thin-Film Cryotrons: Part II-Cryotron Characteristics and Circuit Applications

Part II describes the characteristics of the thin-film cryotron. The superconducting to normal transition in a tin gate 0.125 inch wide and 3 × 10-5 cm thick is controlled by current in a single lead control, 0.006 inch wide, which crosses the gate. Silicon monoxide is used for insulation. The switching time of a cryotron circuit is dependent upon the inductance and resistance of the circuit. Therefore, it is important to reduce the inductance by using a superconductive ground plane and by reducing the length of all interconnecting leads. Nonlocking flip-flops have been constructed, and a ring of five flip-flops have operated with a delay per stage of ½ μsec.