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arXiv · 1506.04053

Fluctuational susceptibility of ultracold bosons in the vicinity of condensation

Arvid J. Kingl·D. M. Gangardt·Igor V. Lerner
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Abstract

We study the behaviour of ultracold bosonic gas in the critical region above the Bose-Einstein condensation in the presence of an artificial magnetic field, $B_\mathrm{art}$. We show that the condensate fluctuations above the critical temperature $T_c$ cause the fluctuational susceptibility, $χ_\mathrm{fl}$, of a uniform gas to have a stronger power-law divergence than in an analogous superconducting system. Measuring such a divergence opens new ways of exploring critical properties of the ultracold gas and an opportunity of an accurate determination of $T_c$. We describe a method of measuring $χ_\mathrm{fl}$ which requires a constant gradient in $B_\mathrm{art}$ and suggest a way of creating such a field in experiment.

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Arvid J. Kingl, D. M. Gangardt, Igor V. Lerner. 2016-05-31. Fluctuational susceptibility of ultracold bosons in the vicinity of condensation. https://doi.org/10.1103/physreva.93.041602

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