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Dephasing by extremely dilute magnetic impurities revealed by Aharonov-Bohm oscillations

F. Pierre·Norman O. Birge
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Abstract

We have probed the magnetic field dependence of the electron phase coherence time $τ_ϕ$ by measuring the Aharonov-Bohm conductance oscillations of mesoscopic Cu rings. Whereas $τ_ϕ$ determined from the low-field magnetoresistance saturates below 1 K, the amplitude of Aharonov-Bohm $h/e$ oscillations increases strongly on a magnetic field scale proportional to the temperature. This provides strong evidence that a likely explanation for the frequently observed saturation of $τ_ϕ$ at low temperature in weakly disordered metallic thin films is the presence of extremely dilute magnetic impurities.

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F. Pierre, Norman O. Birge. 2002-09-24. Dephasing by extremely dilute magnetic impurities revealed by Aharonov-Bohm oscillations. https://doi.org/10.1103/physrevlett.89.206804

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