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Mesoscopic decoherence in Aharonov-Bohm rings

A. E. Hansen·A. Kristensen·S. Pedersen·C. B. Sorensen·P. E. Lindelof
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Abstract

We study electron decoherence by measuring the temperature dependence of Aharonov-Bohm (AB) oscillations in quasi-1D rings, etched in a high-mobility GaAs/GaAlAs heterostructure. The oscillation amplitude is influenced both by phase-breaking and by thermal averaging. Thermal averaging is important when the temperature approaches the energy scale, on which the AB oscillations shift their phase. For the phase-breaking, it is demonstrated that the damping of the oscillation amplitude is proportional to the length of the interfering paths. For temperatures $T$ from 0.3 to 4 $\rm K$ we find the phase coherence length $\it L_ϕ$ $\propto$ $T^{-1}$, close to what has been reported for open quantum dots. This might indicate that the $T^{-1}$ decoherence rate is a general property of open and ballistic mesoscopic systems.

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A. E. Hansen, A. Kristensen, S. Pedersen, C. B. Sorensen, P. E. Lindelof. 2001-05-08. Mesoscopic decoherence in Aharonov-Bohm rings. https://doi.org/10.1103/physrevb.64.045327

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