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arXiv · 1112.3795

Spin Squeezing in Finite Temperature Bose-Einstein Condensates : Scaling with the system size

Alice Sinatra·Emilia Witkowska·Yvan Castin
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Abstract

We perform a multimode treatment of spin squeezing induced by interactions in atomic condensates, and we show that, at finite temperature, the maximum spin squeezing has a finite limit when the atom number $N\to \infty$ at fixed density and interaction strength. To calculate the limit of the squeezing parameter for a spatially homogeneous system we perform a double expansion with two small parameters: 1/N in the thermodynamic limit and the non-condensed fraction $ /N$ in the Bogoliubov limit. To test our analytical results beyond the Bogoliubov approximation, and to perform numerical experiments, we use improved classical field simulations with a carefully chosen cut-off, such that the classical field model gives for the ideal Bose gas the correct non-condensed fraction in the Bose-condensed regime.

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Alice Sinatra, Emilia Witkowska, Yvan Castin. 2012-05-02. Spin Squeezing in Finite Temperature Bose-Einstein Condensates : Scaling with the system size. https://doi.org/10.1140/epjst%2Fe2012-01536-0

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