Gap suppression devices

In this paper we discuss some general features of three terminal superconducting devices which operate on the basis of superconducting energy gap suppression by quasiparticle injection. These features include latching behavior at greater than unity power gain and, in the conventional three layer sandwich geometry, a rather long device switching time. We then describe three terminal gap suppression experiments carried out with the use of a double edge junction geometry. The problems of obtaining large gain in this higher speed geometry are discussed. Finally, we point out that these problems are alleviated by using the gap suppression effect to switch a supercurrent biased junction rather than to modify the quasiparticle I-V curve.