Linked cluster expansion of a qubit decoherence

ORAL

Abstract

We present a theoretical approach to study evolution of a qubit affected by a coupling with a spin bath. The procedure based on a linked cluster decomposition of system and bath dynamics. Unlike previous studies the approach allows exact evaluation of terms of each perturbative order in the exponent contributing to qubit decoherence and phase fluctuations. The procedure has a simple diagrammatic representation. We have utilized the theory to evaluate decoherence of a localized electron spin subject to an interaction with a nuclear spin bath. The novel results we report on are effects of nuclear spin clusters on electrons spin decoherence beyond pair correlation models and also control for dissipation processes in a spin environment.

*The work was supported by the NSF grant DMR-0403465 and ARO/NSA-LPS.

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Authors

  • Semion Saikin

    • University of California, San Diego

  • Wang Yao

    • University of Texas, Austin

  • L.J. Sham

    • University of California, San Diego
    • University of California San Diego
    • Department of Physics, The University of California, San-Diego,La Jolla, California 92093
    • Department of Physics, University of California, San Diego, La Jolla, California, 92093-0319