Significant two-body losses are observed in an ultracold gas of ${}^{85}$ Rb or ${}^{87}$ Rb atoms in a crossed dipole trap implemented with a broadband laser with a wavelength around 1071 nm. Using available spectroscopic data on the excited states of Rb ${}_{2}$ , as well as accurate computed transition dipole moment functions, we interpret these losses as due to photoassociation of deeply bound levels of the 0 ${}_{u}^{+}$ coupled states by the trapping laser, followed by spontaneous emission down to bound levels of the Rb ${}_{2}$ ground state thus forming ultracold molecules. The observed ratio of 3.3 between the loss rates of ${}^{87}$ Rb and ${}^{85}$ Rb is well reproduced by the theoretical model.Significant two-body losses are observed in an ultracold gas of ${}^{85}$Rb or ${}^{87}$Rb atoms in a crossed dipole trap implemented with a broadband laser with a wavelength around 1071 nm. Using available spectroscopic data on the excited states of Rb${}_{2}$, as well as accurate computed transition dipole moment functions, we interpret these losses as due to photoassociation of deeply bound levels of the 0${}_{u}^{+}$ coupled states by the trapping laser, followed by spontaneous emission down to bound levels of the Rb${}_{2}$ ground state thus forming ultracold molecules. The observed ratio of 3.3 between the loss rates of ${}^{87}$Rb and ${}^{85}$Rb is well reproduced by the theoretical model.

Physical Review AMay 8, 201324 citations

Near-threshold photoassociation of Rb2 at very high resolution,

M. Kemmann, Ivan Mistrík, S. Nußmann +1 more

Jan 1, 20020 citations

Significant two-body losses are observed in an ultracold gas of

{}^{85}

Rb or

{}^{87}

Rb atoms in a crossed dipole trap implemented with a broadband laser with a wavelength around 1071 nm. Using available spectroscopic data on the excited states of Rb

{}_{2}

, as well as accurate computed transition dipole moment functions, we interpret these losses as due to photoassociation of deeply bound levels of the 0

{}_{u}^{+}

coupled states by the trapping laser, followed by spontaneous emission down to bound levels of the Rb

{}_{2}

ground state thus forming ultracold molecules. The observed ratio of 3.3 between the loss rates of

{}^{87}

Rb and

{}^{85}

Rb is well reproduced by the theoretical model.