Controlling a mesoscopic spin environment by quantum bit manipulation

TitleControlling a mesoscopic spin environment by quantum bit manipulation
Publication TypeJournal Article
Year of Publication2003
AuthorsTaylor, JM, Imamoglu, A, Lukin, MD
JournalPhysical Review Letters
Date Published2003/12/10

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.

Short TitlePhys. Rev. Lett.