Lifetime of the Bose Gas with Resonant Interactions

Benno S. Rem, Andrew T. Grier, Igor Ferrier-Barbut, Ulrich Eismann, Tim Langen, Nir Navon, Lev Khaykovich, Félix Werner, D. S. Petrov, F. Chevy

Abstract

We study the lifetime of a Bose gas at and around unitarity using a Feshbach resonance in lithium 7. At unitarity, we measure the temperature dependence of the three-body decay coefficient ${L}_{3}$. Our data follow a ${L}_{3}={\ensuremath{\lambda}}_{3}/{T}^{2}$ law with ${\ensuremath{\lambda}}_{3}=2.5(3{)}_{\mathrm{stat}}(6{)}_{\mathrm{syst}}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}20}\text{ }\text{ }(\ensuremath{\mu}\mathrm{K}{)}^{2}\text{ }{\mathrm{cm}}^{6}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ and are in good agreement with our analytical result based on zero-range theory. Varying the scattering length $a$ at fixed temperature, we investigate the crossover between the finite-temperature unitary region and the previously studied regime where $|a|$ is smaller than the thermal wavelength. We find that ${L}_{3}$ is continuous across the resonance, and over the whole $a<0$ range our data quantitatively agree with our calculation.

Locations

• Physical Review Letters - View
• arXiv (Cornell University) - View - PDF
• HAL (Le Centre pour la Communication Scientifique Directe) - View - PDF
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