Frequency dependence of<i>h</i>/<i>e</i>conductance oscillations in mesoscopic Ag rings

Abstract

We have measured the complex magnetoconductance of disordered mesoscopic Ag rings at frequencies from 250 Hz to 1.2 GHz. Conductance oscillations with flux period h/e are observed over the entire frequency range. No suppression of the h/e amplitude is seen up to our highest measurement frequency, even though it is several times the inverse sample transit time ${\mathrm{\ensuremath{\tau}}}_{\mathit{L}}^{\mathrm{\ensuremath{-}}1}$. An h/e-periodic imaginary part of the conductance is observed at frequencies \ensuremath{\omega}\ensuremath{\gtrsim}${\mathrm{\ensuremath{\tau}}}_{\mathit{L}}^{\mathrm{\ensuremath{-}}1}$. The results suggest that the h/e oscillation would only be suppressed if \ensuremath{\omega} were greater than both ${\mathrm{\ensuremath{\tau}}}_{\mathit{L}}^{\mathrm{\ensuremath{-}}1}$ and the thermal frequency kT/\ensuremath{\Elzxh}.