Suppressing Spin Qubit Dephasing by Nuclear State Preparation

Posted on 5 septiembre 2008

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D. J. Reilly, J. M. Taylor, J. R. Petta, C. M. Marcus, M. P. Hanson and A. C. Gossard

Coherent spin states in semiconductor quantum dots offer promise as electrically controllable quantum bits (qubits) with scalable fabrication. For few-electron quantum dots made from gallium arsenide (GaAs), fluctuating nuclear spins in the host lattice are the dominant source of spin decoherence. We report a method of preparing the nuclear spin environment that suppresses the relevant component of nuclear spin fluctuations below its equilibrium value by a factor of ~70, extending the inhomogeneous dephasing time for the two-electron spin state beyond 1 μ s. The nuclear state can be readily prepared by electrical gate manipulation and persists for > 10 s.

Publicado en la revista Science.

Disponible en:

Science Magazine
ArXiv
Harvard University

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