Superconducting proximity effect in mesoscopic superconductor/normal-metaljunctions

The superconducting proximity effect is discussed in mesoscopic superconduc tor/normaI-metal junctions. The newly-developed theory shows long-range pha se-coherent effect which explaines early experimental results of giant magn etoresistance oscillations in an Andreev interferometer. The theory also sh ows that the proximity correction to the conductance (PCC) has a reentrant behavior as a function of energy. The reentrant behavior is systematically studied in a gated superconductor-semiconductor junction. A negative PCC is observed in the case of a weak coupling between the normal metal and the e xternal reservoir. Phase coherent ac effect is also observed when rf is irr adiated to the junction.