Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)

Interacting Rubidium and Caesium Atoms

Claudia Weber, M. Haas, Shincy John, Vanessa Y. F. Leung, L. Steffens, D. Haubrich, A. Rauschenbeutet, Dieter Meschede

Published Jun 1, 2007• 0 citations

Abstract

Binary mixtures of ultracold atoms are of great interest in the research field of quantum optics and are studied by several groups aiming at different applications. This paper works with rubidium and caesium, which are simultaneously stored in a magnetic trap. Species-selective microwave cooling is used on the rubidium groundstate hyperfine transition. Caesium is sympathetically cooled via elastic collisions with rubidium. When cooling down the mixture to temperatures below 1 muK, below 4 muK we observe strong losses of caesium. Analysing the dynamics of sympathetic cooling, lower limit for the modulus of the rubidium-caesium triplet s-wave scattering length is estimated.

DOI: 10.1109/cleoe-iqec.2007.4386716

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Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)

Interacting Rubidium and Caesium Atoms

Claudia Weber, M. Haas, Shincy John, Vanessa Y. F. Leung, L. Steffens, D. Haubrich, A. Rauschenbeutet, Dieter Meschede

Published Jun 1, 2007• 0 citations

Publisher

Abstract

DOI: 10.1109/cleoe-iqec.2007.4386716

Related papers

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arXiv:cond-mat/0410565Physical Review AJun 1, 200554 citations

We present a model for the collisional properties of a mixture of

^{133}\mathrm{Cs}

and

^{87}\mathrm{Rb}

atoms in a magnetic trap at $\ensuremath{\mu}\mathrm{K}$ temperatures. The experimental sequence we model corresponds to a selective evaporation of the Rb atoms using a radio-frequency field, leading to sympathetic cooling of the Cs atoms or, if selective evaporation is carried out fast, to a difference in temperature between the two atomic species. In the latter case, the two atomic clouds reached an equilibrium temperature starting from an Rb temperature lower than that of Cs. By supposing that each atomic cloud was in thermal equilibrium we modeled this rethermalization process through differential equations for the two atomic temperatures. An alternative approach was based on the Monte Carlo simulations of the individual collisional processes. The sympathetic cooling and the rethermalization were analyzed in terms of the inter-species collisional cross-section.

We report on measurements of the collisional properties of a mixture of

^{133}\mathrm{Cs}

and

^{87}\mathrm{Rb}

atoms in a magnetic trap at $\ensuremath{\mu}\mathrm{K}$ temperatures. By selectively evaporating the Rb atoms using a radio-frequency field, we achieved sympathetic cooling of Cs down to a few $\ensuremath{\mu}\mathrm{K}$. The interspecies collisional cross section was determined through rethermalization measurements, leading to good agreement with a theoretical prediction of

595{a}_{0}

for the triplet

s

-wave scattering length for Rb in the $\ensuremath{\mid}F=2,{m}_{F}=2⟩$ and Cs in the $\ensuremath{\mid}F=4,{m}_{F}=4⟩$ magnetic states. We briefly speculate on the prospects for reaching the Bose-Einstein condensation of Cs inside a magnetic trap through sympathetic cooling.