arXiv:cond-mat/0308459 · Physical Review Letters

Controlling a Mesoscopic Spin Environment by Quantum Bit Manipulation

Jacob M. Taylor, Ataç İmamoğlu, Mikhail D. Lukin

Published Dec 10, 2003• 130 citations

Abstract

We present a unified description of cooling and manipulation of a mesoscopic bath of nuclear spins via coupling to a single quantum system of electronic spin (quantum bit). We show that a bath cooled by the quantum bit rapidly saturates. Although the resulting saturated states of the spin bath ("dark states") generally have low degrees of polarization and purity, their symmetry properties make them a valuable resource for the coherent manipulation of quantum bits. Specifically, we demonstrate that the dark states of nuclear ensembles can be used to coherently control the system-bath interaction and to provide a robust, long-lived quantum memory for qubit states.

DOI: 10.1103/physrevlett.91.246802

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