Analysis of the threshold characteristics of the uniform Josephson flux shuttle

A general method for calculating the mode boundaries of a uniform flux shuttle and numerical techniques for computing these thresholds are presented. A number of examples of practical interest are given, including the current distribution in a shuttle due to a single vortex, and static margins of directly injected two-phase shift registers and magnetically clocked three-phase shift registers. Comparison with dynamic circuit simulations shows that the static thresholds are good approximations over a wide range of junction parameters.<
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