Effect of partial phase coherence on Aharonov-Bohm oscillations in metal loops

Abstract

The averaging of Aharonov-Bohm oscillations caused by incomplete phase coherence has been studied in two Sb rings. In these devices, the phase-coherence length ${L}_{\ensuremath{\varphi}}$ can be determined independently from an analysis of the weak localization contribution to the magnetoconductance ($\ensuremath{\Delta}{G}_{C}$) or from the amplitude of the conductance fluctuations. We find that the Aharonov-Bohm oscillations decrease as $\mathrm{exp}(\ensuremath{-}\frac{L}{{L}_{\ensuremath{\varphi}}})$ where $L$ is the sample length. The values of ${L}_{\ensuremath{\varphi}}$ inferred from $\ensuremath{\Delta}{G}_{C}$ qualitatively predict the temperature dependence of the conductance fluctuations.