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Dephasing of Electrons by Two-Level Defects in Quantum Dots

Kang-Hun Ahn·Pritiraj Mohanty
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Abstract

The electron dephasing time $τ_ϕ$ in a diffusive quantum dot is calculated by considering the interaction between the electron and dynamical defects, modelled as two-level system. Using the standard tunneling model of glasses, we obtain a linear temperature dependence of $1/τ_ϕ$, consistent with the experimental observation. However, we find that, in order to obtain dephasing times on the order of nanoseconds, the number of two-level defects needs to be substantially larger than the typical concentration in glasses. We also find a finite system-size dependence of $τ_ϕ$, which can be used to probe the effectiveness of surface-aggregated defects.

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Kang-Hun Ahn, Pritiraj Mohanty. 2000-11-08. Dephasing of Electrons by Two-Level Defects in Quantum Dots. https://doi.org/10.1103/physrevb.63.195301

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