Unbound MEDLINE

Persistent narrowing of nuclear-spin fluctuations in InAs quantum dots using laser excitation.

Abstract

We demonstrate the suppression of nuclear-spin fluctuations in an InAs quantum dot and measure the timescales of the spin narrowing effect. By initializing for tens of milliseconds with two continuous wave diode lasers, fluctuations of the nuclear spins are suppressed via the hole-assisted dynamic nuclear polarization feedback mechanism. The fluctuation narrowed state persists in the dark (absent light illumination) for well over 1 s even in the presence of a varying electron charge and spin polarization. Enhancement of the electron spin coherence time (T2*) is directly measured using coherent dark state spectroscopy. By separating the calming of the nuclear spins in time from the spin qubit operations, this method is much simpler than the spin echo coherence recovery or dynamic decoupling schemes.

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  • Publisher Full Text

    • Authors

    Sun B, Chow CM, Steel DG, Bracker AS, Gammon D, Sham LJ

    Institution

    The H. M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109, USA.

    Source

    Physical review letters 108:18 2012 May 4 pg 187401

    Pub Type(s)

    Journal Article

    Language

    eng

    PubMed ID

    22681117