Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:cond-mat/0410565 · Physical Review A

Sympathetic cooling and collisional properties of a Rb‐Cs mixture

Marco Anderlini, E. Courtade, Matteo Cristiani, D. Cossart, D. Ciampini, Carlo Sias, O. Morsch, E. Arimondo

Published Jun 1, 2005• 54 citations
arXivHTMLPDF

Abstract

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.

DOI
10.1103/physreva.71.061401

Related papers

Model for collisions in ultracold-atom mixtures

Marco Anderlini, D. Ciampini, D. Cossart +5 more

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.

Physical Review A•Sep 14, 2005•16 citations

An ultra-cold rb-cs mixture in a magnetic trap

D. Ciampini, Marco Anderlini, E. Courtade +5 more

This works reports on using laser cooling and evaporative cooling to create an ultra-cold mixture of /sup 87/Rb and /sup 133/Cs atoms inside the conservative potential of a time-averaged orbiting potential (TOP) magnetic trap. We were able to observe sympathetic cooling of Cs through collisional energy exchange with the Rb atoms, thus reaching Cs temperatures of /spl ap/ 5 /spl mu/K.

European Quantum Electronics Conference (EQEC)•Jan 18, 2006•0 citations

Species-selective microwave cooling of a mixture of rubidium and caesium atoms

M Haas, Vanessa Y. F. Leung, Daniel Frese +5 more

We have sympathetically cooled a small sample of 133 Cs atoms with 87 Rb to below 1 μK. Evaporative cooling was realized with microwave radiation driving the Rb ground-state hyperfine transition. By analysing the sympathetic cooling dynamics, we derive a lower limit of the modulus of the Rb–Cs interspecies triplet s -wave scattering length of 200 a 0 . For temperatures below 5 μK we observe strong non-exponential losses of the Cs sample in the presence of the Rb sample.

New Journal of Physics•May 23, 2007•30 citations

Collisional Properties of Ultracold K-Rb Mixtures

G. Ferrari, M. Inguscio, W. Jastrzȩbski +3 more

We determine the interspecies $s$-wave triplet scattering length ${a}_{3}$ for all K-Rb isotopic mixtures by measuring the elastic cross section for collisions between $^{\mathrm{41}}\mathrm{K}$ and $^{87}\mathrm{R}\mathrm{b}$ in different temperature regimes. The positive value ${a}_{3}=+{163}_{\ensuremath{-}12}^{+57}{a}_{0}$ ensures the stability against collapse of binary $^{41}\mathrm{K}\ensuremath{-}^{87}\mathrm{R}\mathrm{b}$ Bose-Einstein condensates. For the fermion-boson mixture $^{40}\mathrm{K}\ensuremath{-}^{87}\mathrm{R}\mathrm{b}$, we obtain a large and negative scattering length which implies an efficient sympathetic cooling of the fermionic species down to the degenerate regime.

arXiv:cond-mat/0202290•Physical Review Letters•Jul 15, 2002•140 citations

Sympathetic cooling of 85Rb and 87Rb

Immanuel Bloch, Markus Greiner, Olaf Mandel +2 more

We demonstrate sympathetic cooling between magnetically trapped ${}^{85}\mathrm{Rb}$ and ${}^{87}\mathrm{Rb}$ atoms. Up to $6\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${}^{85}\mathrm{Rb}$ atoms are cooled via elastic collisions with a reservoir of $8\ifmmode\times\else\texttimes\fi{}{10}^{8}$ ${}^{87}\mathrm{Rb}$ atoms. The temperature of the binary atomic ensemble is adjusted by using radio-frequency evaporation of ${}^{87}\mathrm{Rb}.$ Temperatures as low as $T=100 \mathrm{nK}$ have been realized in the binary ensemble. Through a cross-dimensional mixing approach we have been able to measure the interspecies ${}^{87}\mathrm{Rb}{\ensuremath{-}}^{85}\mathrm{Rb}$ scattering cross section $\ensuremath{\sigma}=1.52(34)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15} {\mathrm{m}}^{2}.$

Physical Review A•Jul 10, 2001•75 citations

Prospects for Mixed-Isotope Bose-Einstein Condensates in Rubidium

James P. Burke, John L. Bohn, Brett D. Esry +1 more

We calculate binary collision parameters for mixtures of ultracold gases of ${}^{85}\mathrm{Rb}$ and ${}^{87}\mathrm{Rb}$ atoms. We predict a large positive triplet scattering length for mixed-isotope collisions, which implies that a stable mixed-isotope double condensate can be formed by sympathetic evaporative cooling. Moreover, collisions between ${}^{85}\mathrm{Rb}$ and ${}^{87}\mathrm{Rb}$ atoms in the lowest hyperfine manifold exhibit magnetic-field-induced Feshbach resonances which should allow partial control of the interaction between condensates. These considerations make Rb an ideal system for the study of interpenetrating bosonic superfluids.

Physical Review Letters•Mar 9, 1998•108 citations
We report on measurements of the collisional properties of a mixture of 133Cs^{133}\mathrm{Cs}133Cs and 87Rb^{87}\mathrm{Rb}87Rb atoms in a magnetic trap at \ensuremathμK\ensuremath{\mu}\mathrm{K}\ensuremathμK temperatures. By selectively evaporating the Rb atoms using a radio-frequency field, we achieved sympathetic cooling of Cs down to a few \ensuremathμK\ensuremath{\mu}\mathrm{K}\ensuremathμK. The interspecies collisional cross section was determined through rethermalization measurements, leading to good agreement with a theoretical prediction of 595a0595{a}_{0}595a0​ for the triplet sss-wave scattering length for Rb in the \ensuremath∣F=2,mF=2⟩\ensuremath{\mid}F=2,{m}_{F}=2⟩\ensuremath∣F=2,mF​=2⟩ and Cs in the \ensuremath∣F=4,mF=4⟩\ensuremath{\mid}F=4,{m}_{F}=4⟩\ensuremath∣F=4,mF​=4⟩ magnetic states. We briefly speculate on the prospects for reaching the Bose-Einstein condensation of Cs inside a magnetic trap through sympathetic cooling.
We present a model for the collisional properties of a mixture of 133Cs^{133}\mathrm{Cs}133Cs and 87Rb^{87}\mathrm{Rb}87Rb 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 determine the interspecies sss-wave triplet scattering length a3{a}_{3}a3​ for all K-Rb isotopic mixtures by measuring the elastic cross section for collisions between 41K^{\mathrm{41}}\mathrm{K}41K and 87Rb^{87}\mathrm{R}\mathrm{b}87Rb in different temperature regimes. The positive value ${a}_{3}=+{163}_{\ensuremath{-}12}^{+57}{a}_{0}$ ensures the stability against collapse of binary $^{41}\mathrm{K}\ensuremath{-}^{87}\mathrm{R}\mathrm{b}$ Bose-Einstein condensates. For the fermion-boson mixture $^{40}\mathrm{K}\ensuremath{-}^{87}\mathrm{R}\mathrm{b}$, we obtain a large and negative scattering length which implies an efficient sympathetic cooling of the fermionic species down to the degenerate regime.
We demonstrate sympathetic cooling between magnetically trapped 85Rb{}^{85}\mathrm{Rb}85Rb and 87Rb{}^{87}\mathrm{Rb}87Rb atoms. Up to $6\ifmmode\times\else\texttimes\fi{}{10}^{6}$ 85Rb{}^{85}\mathrm{Rb}85Rb atoms are cooled via elastic collisions with a reservoir of $8\ifmmode\times\else\texttimes\fi{}{10}^{8}$ 87Rb{}^{87}\mathrm{Rb}87Rb atoms. The temperature of the binary atomic ensemble is adjusted by using radio-frequency evaporation of 87Rb.{}^{87}\mathrm{Rb}.87Rb. Temperatures as low as T=100nKT=100 \mathrm{nK}T=100nK have been realized in the binary ensemble. Through a cross-dimensional mixing approach we have been able to measure the interspecies ${}^{87}\mathrm{Rb}{\ensuremath{-}}^{85}\mathrm{Rb}$ scattering cross section $\ensuremath{\sigma}=1.52(34)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15} {\mathrm{m}}^{2}.$
We calculate binary collision parameters for mixtures of ultracold gases of 85Rb{}^{85}\mathrm{Rb}85Rb and 87Rb{}^{87}\mathrm{Rb}87Rb atoms. We predict a large positive triplet scattering length for mixed-isotope collisions, which implies that a stable mixed-isotope double condensate can be formed by sympathetic evaporative cooling. Moreover, collisions between 85Rb{}^{85}\mathrm{Rb}85Rb and 87Rb{}^{87}\mathrm{Rb}87Rb atoms in the lowest hyperfine manifold exhibit magnetic-field-induced Feshbach resonances which should allow partial control of the interaction between condensates. These considerations make Rb an ideal system for the study of interpenetrating bosonic superfluids.