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arXiv · 1707.09832

Correlation function of spin noise due to atomic diffusion

V. G. Lucivero·N. D. McDonough·N. Dural·M. V. Romalis
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Abstract

We use paramagnetic Faraday rotation to study spin noise spectrum from unpolarized Rb vapor in a tightly focused probe beam in the presence of N$_2$ buffer gas. We derive an analytical form for the diffusion component of the spin noise time-correlation function in a Gaussian probe beam. We also obtain analytical forms for the frequency spectrum of the spin noise in the limit of a tightly focused or a collimated Gaussian beam in the presence of diffusion. In particular, we find that in a tightly focused probe beam the spectral lineshape can be independent of the buffer gas pressure. Experimentally, we find good agreement between the calculated and measured spin noise spectra for N$_2$ gas pressures ranging from 56 to 820 torr.

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V. G. Lucivero, N. D. McDonough, N. Dural, M. V. Romalis. 2017-07-31. Correlation function of spin noise due to atomic diffusion. https://doi.org/10.1103/physreva.96.062702

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