Dynamics of some single flux quantum devices: I. Parametric quantron

In this paper and the following one, the properties of two systems operating with single flux quanta are calculated. The first system is a quantron (a one-junction interferometer) with a Josephson gate as a junction. By a proper change of its critical current in time, the switching of quantron stable states can be controlled by a small external flux much less than Φo. This "Parametric Quantron" can be used as the basic cell of a Single Quantum Logic System. The most wonderful property of this device is that the energy dissipation during one logical step (PτT factor) can be much less than the thermal energy KBT and is limited by quantum effects only: Pτ²simg10²h.