A New Configuration for Faster Cryotron Circuits

Mutual inductance is used to reduce the effect of inductance and thus increase speed. If wires are close together when current is switched from one to another, there is very little change in magnetic field, and consequently, very little energy is necessary to do the switching. Therefore, the effective inductance is small. The required close coupling is obtained by depositing one wire of the pair over the other instead of side by side, as is usually done. This permits improvements in electrical time constant, (irreversible) thermal repetition rate limit, and reliability. There are cryotron configurations suitable for use with inductively coupled lines.