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

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 $L_{\phi }$ can be determined independently from an analysis of the weak localization contribution to the magnetoconductance ($\Delta G_C$) or from the amplitude of the conductance fluctuations. We find that the Aharonov-Bohm oscillations decrease as $\exp (-\frac{L}{L_{\phi }})$ where $L$ is the sample length. The values of $L_{\phi }$ inferred from $\Delta G_C$ qualitatively predict the temperature dependence of the conductance fluctuations.