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arXiv · 1103.0413

Motional Broadening in Ensembles With Heavy-Tail Frequency Distribution

Yoav Sagi·Rami Pugatch·Ido Almog·Nir Davidson·Michael Aizenman
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Abstract

We show that the spectrum of an ensemble of two-level systems can be broadened through `resetting' discrete fluctuations, in contrast to the well-known motional-narrowing effect. We establish that the condition for the onset of motional broadening is that the ensemble frequency distribution has heavy tails with a diverging first moment. We find that the asymptotic motional-broadened lineshape is a Lorentzian, and derive an expression for its width. We explain why motional broadening persists up to some fluctuation rate, even when there is a physical upper cutoff to the frequency distribution.

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Yoav Sagi, Rami Pugatch, Ido Almog, Nir Davidson, Michael Aizenman. 2011-03-02. Motional Broadening in Ensembles With Heavy-Tail Frequency Distribution. https://doi.org/10.1103/physreva.83.043821

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