Magnetoresistance of proximity-coupled Au wires - art. no. 187003

Measurements of the proximity coupled An wires show a magnetoresistance tha t is quadratic in the magnetic field B at low field, with a characteristic field scale B-c determined by phase coherent paths which encompass not only the wire, but also the contacts. B-c is essentially temperature independen t at low temperatures, indicating that the area of the phase coherent paths is not determined by the superconducting coherence length L-T in the norma l, metal which is strongly temperature dependent at low temperatures. We id entify the relevant length scale as a combination of the electron phase coh erence length L-phi in the normal metal and the coherence length xi (S) in the superconductor.