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Nonequilibrium stabilization of charge states in double quantum dots

Udo Hartmann·Frank K. Wilhelm
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Abstract

We analyze the decoherence of charge states in double quantum dots due to cotunneling. The system is treated using the Bloch-Redfield generalized master equation for the Schrieffer-Wolff transformed Hamiltonian. We show that the decoherence, characterized through a relaxation $τ_{r}$ and a dephasing time $τ_ϕ$, can be controlled through the external voltage and that the optimum point, where these times are maximum, is not necessarily in equilibrium. We outline the mechanism of this nonequilibrium-induced enhancement of lifetime and coherence. We discuss the relevance of our results for recent charge qubit experiments.

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Udo Hartmann, Frank K. Wilhelm. 2004-04-29. Nonequilibrium stabilization of charge states in double quantum dots. https://doi.org/10.1103/physrevb.69.161309

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