Our lab and experiments

Rb-Cs cold collisions.

The collisional properties of a mixture of boson cesium and rubidium atoms were investigated for the first time in a magnetic trap at ?K temperatures. By selectively evaporating the rubidium atoms using a radio-frequency field, the sympathetic cooling of cesium down to a few ?K was realized. From rethermalization measurements, we derived a very large value for the interspecies collisional cross section was determined, leading to good agreement with a theoretical prediction of 595a0 for the triplet s-wave scattering length for Rb in the |F=2,mF=2> and Cs in the |F=4,mF=4> magnetic states. This value opens prospects for reaching the Bose-Einstein condensation of Cs inside a magnetic trap through the sympathetic cooling.

References:

M. Anderlini, E. Courtade, M. Cristiani, D. Cossart, D. Ciampini, C. Sias, O. Morsch, and E. Arimondo, “Sympathetic cooling and collisional properties of a Rb- Cs mixture”, Phys. Rev. A 71, 061401(R) (2005).

M. Anderlini, D. Ciampini, D. Cossart, E. Courtade, M. Cristiani, C. Sias, O. Morsch, and E. Arimondo, “Model for collisions in ultracold-atom mixtures”, Phys. Rev. A 72, 033408 (2005)

E. Tiesinga, M. Anderlini, and E. Arimondo, “Determination of the scattering length of the a3S+ potential of 87RbCs”, Phys. Rev. A 75, 022707 (2007).