Applying the direct simulation Monte Carlo (DSMC) method developed for the cold atom system, we explore the possibility of a high-efficiency sympathetic cooling process between 87 Rb and 40 K without gravitational force in an optical trap. The relation between the pre-cooling of Bosons and the sympathetic cooling efficiency is also studied. We find that the absence of gravitational force is beneficial to the process of sympathetic cooling. Furthermore, an inefficient pre-cooling process will in fact hamper the creation of Fermi degenerate gases. This suggests the advantages of sympathetic cooling in microgravity.Applying the direct simulation Monte Carlo (DSMC) method developed for the cold atom system, we explore the possibility of a high-efficiency sympathetic cooling process between 87 Rb and 40 K without gravitational force in an optical trap. The relation between the pre-cooling of Bosons and the sympathetic cooling efficiency is also studied. We find that the absence of gravitational force is beneficial to the process of sympathetic cooling. Furthermore, an inefficient pre-cooling process will in fact hamper the creation of Fermi degenerate gases. This suggests the advantages of sympathetic cooling in microgravity.

Chinese Physics LettersApr 1, 20145 citations

Sympathetic Cooling in an Optically Trapped Mixture of Alkali and Spin-Singlet Atoms

V. V. Ivanov, Alexander Y. Khramov, Anders H. Hansen +4 more

We report on the realization of a stable mixture of ultracold lithium and ytterbium atoms confined in a far-off-resonance optical dipole trap. We observe sympathetic cooling of $^{6}\mathrm{Li}$ by $^{174}\mathrm{Yb}$ and extract the $s$ -wave scattering length magnitude $|{a}_{^{6}\mathrm{Li}\mathrm{\text{\ensuremath{-}}}^{174}\mathrm{Yb}}|=(13\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ from the rate of interspecies thermalization. Using forced evaporative cooling of $^{174}\mathrm{Yb}$ , we achieve reduction of the $^{6}\mathrm{Li}$ temperature to below the Fermi temperature, purely through interspecies sympathetic cooling.We report on the realization of a stable mixture of ultracold lithium and ytterbium atoms confined in a far-off-resonance optical dipole trap. We observe sympathetic cooling of $^{6}\mathrm{Li}$ by $^{174}\mathrm{Yb}$ and extract the $s$-wave scattering length magnitude $|{a}_{^{6}\mathrm{Li}\mathrm{\text{\ensuremath{-}}}^{174}\mathrm{Yb}}|=(13\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ from the rate of interspecies thermalization. Using forced evaporative cooling of $^{174}\mathrm{Yb}$, we achieve reduction of the $^{6}\mathrm{Li}$ temperature to below the Fermi temperature, purely through interspecies sympathetic cooling.

arXiv:1101.5142Physical Review LettersApr 11, 201171 citations

Adiabatic cooling of atoms trapped in a transformable optical trap

Seung‐Koo Lee, Hui Dong Kim, Sin Hyuk Yim +1 more

Bulletin of the American Physical SocietyJun 8, 20070 citations

Optimized sympathetic cooling of atomic mixtures via fast adiabatic strategies

Stephen U. S. Choi, Roberto Onofrio, Bala Sundaram

We discuss fast frictionless cooling techniques in the framework of sympathetic cooling of cold atomic mixtures. It is argued that optimal cooling of an atomic species---in which the deepest quantum degeneracy regime is achieved---may be obtained by means of sympathetic cooling with another species whose trapping frequency is dynamically changed to maintain constancy of the Lewis-Riesenfeld adiabatic invariant. Advantages and limitations of this cooling strategy are discussed, with particular regard to the possibility of cooling Fermi gases to a deeper degenerate regime.We discuss fast frictionless cooling techniques in the framework of sympathetic cooling of cold atomic mixtures. It is argued that optimal cooling of an atomic species---in which the deepest quantum degeneracy regime is achieved---may be obtained by means of sympathetic cooling with another species whose trapping frequency is dynamically changed to maintain constancy of the Lewis-Riesenfeld adiabatic invariant. Advantages and limitations of this cooling strategy are discussed, with particular regard to the possibility of cooling Fermi gases to a deeper degenerate regime.

arXiv:1109.4908Physical Review ANov 9, 201148 citations

We report on the realization of a stable mixture of ultracold lithium and ytterbium atoms confined in a far-off-resonance optical dipole trap. We observe sympathetic cooling of

^{6}\mathrm{Li}

^{174}\mathrm{Yb}

and extract the

s

-wave scattering length magnitude $|{a}_{^{6}\mathrm{Li}\mathrm{\text{\ensuremath{-}}}^{174}\mathrm{Yb}}|=(13\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ from the rate of interspecies thermalization. Using forced evaporative cooling of

^{174}\mathrm{Yb}

, we achieve reduction of the

^{6}\mathrm{Li}

temperature to below the Fermi temperature, purely through interspecies sympathetic cooling.