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arXiv:0910.4447 · New Journal of Physics

Resonant scattering effect in spectroscopies of interacting atomic gases

M J Leskinen, J Kajala, J. J. Kinnunen

Published Aug 17, 2010• 5 citations
arXivHTMLPDF

Abstract

We consider spectroscopies of strongly interacting atomic gases, and we propose a model for describing the coupling between quasiparticles and gapless phonon-like modes. Our model explains features in a wide range of different experiments in both fermionic and bosonic atom gases in various spectroscopic methods.
DOI
10.1088/1367-2630/12/8/083041

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We investigate properties of an energetic atom propagating through strongly interacting atomic gases. The operator product expansion is used to systematically compute a quasiparticle energy and its scattering rate both in a spin-1/2 Fermi gas and in a spinless Bose gas. Reasonable agreement with recent quantum Monte Carlo simulations even at a relatively small momentum $k/{k}_{\mathrm{F}}\ensuremath{\gtrsim}1.5$ indicates that our large-momentum expansions are valid in a wide range of momentum. We also study a differential scattering rate when a probe atom is shot into atomic gases. Because the number density and current density of the target atomic gas contribute to the forward scattering only, its contact density (measure of short-range pair correlation) gives the leading contribution to the backward scattering. Therefore, such an experiment can be used to measure the contact density and thus provides a new local probe of strongly interacting atomic gases.