Giant conductance oscillations controlled by supercurrent flow through a ballistic mesoscopic conductor

Abstract

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 Δφ. In contrast to the case of diffusive transport the amplitude of the oscillations can greatly exceed both ${\mathit{e}}^2$/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.