Instituto de Ciencia de Materiales de Madrid
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Intrinsic phonon decoherence and quantum gates in coupled lateral quantum dot charge qubits

Markus J. Storcz, Udo Hartmann, Sigmund Kohler, and Frank K. Wilhelm
Phys. Rev. B 72, 235321 (2005)

Recent experiments by Hayashi et al. [Phys. Rev. Lett. 91, 226804 (2003)] demonstrate coherent oscillations of a charge quantum bit (qubit) in laterally defined quantum dots. We study the intrinsic electron-phonon decoherence and gate performance for the next step: a system of two coupled charge qubits. The effective decoherence model contains properties of local as well as collective decoherence. We show that due to the super-Ohmic spectrum, the gate quality is limited by the single-qubit Hadamard gates. It can be significantly improved, by using double-dots with weak tunnel coupling.

[ICMM-CSIC] [Condensed Matter Theory]
last modified: 15.3.2024 by Sigmund Kohler