Amplitude of Aharonov-Bohm oscillations in mesoscopic metallic rings as a function of the DC bias voltage

We report measurements of the amplitude of the Aharonov-Bohm oscillations in a mesoscopic diffusive gold ring as a function of the DC bias voltage V. The amplitude of the h/e oscillations increases with V once the Thouless energy Ec and thermal energy are exceeded, and decreases at higher values of V. The increase of the amplitude is interpreted in terms of a superposition of the statistically independent contributions of eV/Ec energy intervals, whereas its decrease at high V could be attributed to enhanced inelastic scattering processes.