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arXiv · 0809.0003

Electron Spin Dephasing due to Hyperfine Interactions with a Nuclear Spin Bath

L. Cywinski·W. M. Witzel·S. Das Sarma
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Abstract

We investigate pure dephasing decoherence (free induction decay and spin echo) of a spin qubit interacting with a nuclear spin bath. While for infinite magnetic field B the only decoherence mechanism is spectral diffusion due to dipolar flip-flops of nuclear spins, with decreasing B the hyperfine-mediated interactions between the nuclear spins become important. We give a theory of decoherence due to these interactions which takes advantage of their long-range nature. For a thermal uncorrelated bath we show that our theory is applicable down to B~10 mT, allowing for comparison with recent experiments in GaAs quantum dots.

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L. Cywinski, W. M. Witzel, S. Das Sarma. 2009-02-03. Electron Spin Dephasing due to Hyperfine Interactions with a Nuclear Spin Bath. https://doi.org/10.1103/physrevlett.102.057601

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