Frontiers in Optics

Experiments with Trapped Ultracold RbCs Molecules

Eric R. Hudson

Published Jan 1, 2008• 0 citations

Abstract

Dense samples of ultracold heteronuclear molecules, produced via atomic photoassociation, have been trapped in an optical lattice. We report on recent measurements of inelastic collision rates for these molecules with both Rb and Cs atoms.

DOI: 10.1364/ls.2008.lwj2

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Frontiers in Optics

Experiments with Trapped Ultracold RbCs Molecules

Eric R. Hudson

Published Jan 1, 2008• 0 citations

Publisher

Abstract

DOI: 10.1364/ls.2008.lwj2

Related papers

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Ultracold collisions between Cs atoms and

{\mathrm{Cs}}_{2}

dimers in the electronic ground state are observed in an optically trapped gas of atoms and molecules. The

{\mathrm{Cs}}_{2}

molecules are formed in the triplet ground state by cw photoassociation through the outer well of the ${0}_{g}^{\ensuremath{-}}({P}_{3/2})$ excited electronic state. Inelastic atom-molecule collisions converting internal excitation into kinetic energy lead to a loss of

{\mathrm{Cs}}_{2}

molecules from the dipole trap. Rate coefficients are determined for collisions involving Cs atoms in either the

F=3

F=4

hyperfine ground state, and

{\mathrm{Cs}}_{2}

molecules in either highly vibrationally excited states (${v}^{\ensuremath{'}}=32--47$) or in low vibrational states (${v}^{\ensuremath{'}}=4--6$) of the $a\text{ }^{3}\ensuremath{\Sigma}_{u}^{+}$ triplet ground state. The rate coefficients $\ensuremath{\beta}\ensuremath{\sim}{10}^{\ensuremath{-}10}\text{ }\text{ }{\mathrm{cm}}^{3}/\mathrm{s}$ are found to be largely independent of the vibrational and rotational excitation indicating unitary limited cross sections.

We have produced ultracold, polar

{\mathrm{R}\mathrm{b}\mathrm{C}\mathrm{s}}^{*}

molecules via photoassociation in a laser-cooled mixture of Rb and Cs atoms. Using a model of the

{\mathrm{R}\mathrm{b}\mathrm{C}\mathrm{s}}^{*}

molecular interaction which reproduces the observed rovibrational structure, we infer decay rates in our experiments into deeply bound $X\text{ }^{1}\ensuremath{\Sigma}^{+}$ ground-state RbCs vibrational levels as high as $5\ifmmode\times\else\texttimes\fi{}{10}^{5}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ per level. Population in such deeply bound levels could be efficiently transferred to the vibrational ground state using a single stimulated Raman transition, opening the possibility to create large samples of stable, ultracold polar molecules.

\text{Rb}(5{S}_{1/2})+\text{Cs}(6{P}_{3/2})

dissociation limit gives information on the state responsible for molecule formation. The molecules are mainly formed in deeply bound levels of the electronic triplet ground state. The observed photoassociation transitions present differences in terms of saturation.