GIANT CONDUCTANCE OSCILLATIONS CONTROLLED BY SUPERCURRENT FLOW-THROUGH A BALLISTIC MESOSCOPIC CONDUCTOR

We predict giant conductance oscillations for a normal ballistic sample in contact with superconducting elements. The effect is due to quasiparticle interference leading to a resonant sensitivity of the normal current to the superconductor phase difference Delta phi. In contrast to the case of diffusive transport the amplitude of the oscillations can greatly exceed both e(2)/h and the conductance of the system itself measured in absence of superconducting elements. We suggest an experiment where the effect can be revealed most dramatically. A simple relation between the resonant conductance and the Josephson current through the system is derived.