Coherence of Donor Electron Spins in Isotopically Enriched Silicon

ORAL

Abstract

Silicon is promising for spin-based quantum computing because nuclear spins, a source of magnetic noise, may be nearly eliminated through enrichment. However, any Si device is expected to contain some phosphorus donor impurities. These donors generate magnetic noise through spin dynamics, induced by dipolar interactions, that conserve Zeeman and hyperfine energies. Ironically, increasing the number of nuclear spins will suppress this decoherence mechanism by effecting more hyperfine energy variation (i.e., Overhauser shifts). We study spin coherence decay as a function of donor concentration, $^{29}$Si concentration, and temperature using cluster expansion techniques specifically adapted to the problem of a sparse electron spin bath.

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Authors

  • Wayne Witzel

    Sandia National Laboratories, Sandia National Laboratories, New Mexico, USA

  • Richard Muller

    Sandia National Laboratories, New Mexico, USA, Sandia National Laboratories, Albuquerque, NM 87185, USA

  • Malcolm Carroll

    Sandia National Laboratories, Sandia National Laboratories, New Mexico, USA, Sandia National Laboratories, Albuquerque, NM 87185, USA

  • Andrea Morello

    The University of New South Wales, Sydney, Australia, University of New South Wales

  • Lukasz Cywinski

    Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland and Condensed Matter Theory Center, University of Maryland, USA

  • S. Das Sarma

    University of Maryland, Condensed Matter Theory Center and Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, MD 20742, Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland, USA, University of Maryland, College Park, University of Maryland-College Park, Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park MD 20742-4111, Univ. of Maryland, University of Maryland, College Park, Maryland, USA, Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742-4111