Quantum corrections to 3-body recombination in a dilute Bose-Einstein condensate

Brett D. Esry

正仁 上田, Masahito Ueda

航 河野

Eric Braaten, H.‐W. Hammer, Thomas Mehen

We study a dilute Bose gas of atoms whose scattering length a is large compared to the range of their interaction. We calculate the energy density E of a homogeneous Bose-Einstein condensate (BEC) to second order in the low-density expansion, expressing it in terms of a and a second parameter Lambda* that determines the low-energy observables in the three-body sector. The second-order correction to E has a small imaginary part that reflects the instability due to three-body recombination. In the case of a trapped BEC with large negative a, we calculate the coefficient of the three-body mean-field term in E in terms of a and Lambda*. It can be very large if there is an Efimov state near threshold.

Eric A. Burt, R. W. Ghrist, Christopher J. Myatt +3 more

We have used three-body recombination rates as a sensitive probe of the statistical correlations between atoms in Bose-Einstein condensates (BEC) and in ultracold noncondensed dilute atomic gases. We infer that density fluctuations are suppressed in the BEC samples. We measured the three-body recombination rate constants for condensates and cold noncondensates from number loss in the ${F\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1,m}_{f}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}1$ hyperfine state of ${}^{87}\mathrm{Rb}$. The ratio of these is $7.4(2.6)$ which agrees with the theoretical factor of $3!$ and demonstrates that condensate atoms are less bunched than noncondensate atoms.

Olivier Tiokeng Lekeufack, Subramaniyan Sabari, Serge Bruno Yamgoué +2 more