''Proximity'' effect in the conductance of mesoscopic normal metal-superconductor structures

To clarify the nature of the interference effects observed in mesoscopic normal metal-superconductor structures the properties of silver wires with three types of superconducting loops at the stubs were experimentally studied. The geometry of the structures was chosen to enhance the main features of the transport in such systems and verify the models proposed for the interference phenomena. We observed behavior consistent with the proximity model. The role of the condensate, induced in the normal part by the superconductor, is discussed in the framework of this model.