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Bose-Einstein Condensates in the Large Gas Parameter Regime

A. Fabrocini·A. Polls
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Abstract

Bose-Einstein condensates of 10$^4$ $^{85}$Rb atoms in a cylindrical trap are studied using a recently proposed modified Gross-Pitaevskii equation. The existence of a Feshbach resonance allows for widely tuning the scattering length of the atoms, and values of the peak gas parameter, $x_{pk}$, of the order of 10$^{-2}$ can be attained. We find large differences between the results of the modified Gross-Pitaevskii and of the standard Thomas-Fermi, and Gross-Pitaevskii equations in this region. The column densities at $z=0$ may differ by as much as $\sim 30%$ and the half maximum radius by $\sim 20%$. The scattering lengths estimated by fitting the half maximum radius within different approaches can differ by $\sim 40%$.

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A. Fabrocini, A. Polls. 2001-01-25. Bose-Einstein Condensates in the Large Gas Parameter Regime. https://doi.org/10.1103/physreva.64.063610

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