MESOSCOPIC SUPERCONDUCTING-NORMAL METAL SUPERCONDUCTING TRANSISTOR

In a mesoscopic superconductor- normal metal - superconductor (SNS) he terostructure the quasiparticle distribution can be driven far from eq uilibrium by a voltage applied across the normal metal. This reduces t he supercurrent between the superconducting electrodes, which creates the possibility of using these SNS junctions as fast switches and tran sistors. We describe the system in the framework of the quasiclassical theory and find,good a,agreement with recent experiments. We propose further experimental tests, for instance, the voltage dependence of th e current-phase relation, which includes a transition to a pi junction . [S0031-9007(98)06894-X].