Dephasing of a quantum dot due to the Coulomb interaction with a gate electrode

Dephasing of quantum dots presents an intrinsic limitation on their use for quantum computing. We consider the dephasing of a double quantum dot caused by the Coulomb interaction with nearby gate electrodes and show that this occurs on a much longer time scale than dephasing due to phonons. However, the effect grows rapidly stronger as the system size decreases, and therefore it is expected to limit potential miniaturization of these systems.