Anomalous magnetoresistance of partially superconducting mesoscopic loop

The magnetoresistance of a silver loop, a part of which was replaced by superconducting aluminum, was measured. The h/2e conductance oscillations whose amplitude increased to about 400(e(2)/h) at T = 0.1 K were observed. The samples exhibited nonlinear I-V characteristics at low temperatures and the oscillations were inverted when the current was increased. The anomalous negative magnetoresistance was also observed at low fields at the lowest temperatures.