We report the observation of interspecies Feshbach resonances in an optically trapped mixture of ${}^{85}$ Rb and ${}^{133}$ Cs. We measure nine resonances in the lowest spin channel for a magnetic field range from 0 to 700 G and show that they are in good agreement with coupled-channel calculations. The interspecies background scattering length is close to zero over a large range of magnetic fields, permitting the sensitive detection of Feshbach resonances through interspecies thermalization. Our results confirm the quality of the Rb-Cs potential curves [Phys. Rev. A 85, 032506 (2012)] and offer promising starting points for the production of ultracold polar molecules.We report the observation of interspecies Feshbach resonances in an optically trapped mixture of ${}^{85}$Rb and ${}^{133}$Cs. We measure nine resonances in the lowest spin channel for a magnetic field range from 0 to 700 G and show that they are in good agreement with coupled-channel calculations. The interspecies background scattering length is close to zero over a large range of magnetic fields, permitting the sensitive detection of Feshbach resonances through interspecies thermalization. Our results confirm the quality of the Rb-Cs potential curves [Phys. Rev. A 85, 032506 (2012)] and offer promising starting points for the production of ultracold polar molecules.

arXiv:1208.4569Physical Review AJan 11, 201332 citations

Experimental Investigation of Two-color Polarization Spectroscopy in Rubidium

P. Kulatunga, Lindsey Andrews, Charles I. Sukenik +1 more

Bulletin of the American Physical SocietyJun 14, 20110 citations

Photoassociative Production and Detection of Ultracold Polar RbCs Molecules

Zhonghua Ji, Hongshan Zhang, Jizhou Wu +6 more

We have produced ultracold polar RbCs molecules via photoassociation starting from laser-cooled 85 Rb and 133 Cs atoms in a dual-species, forced dark magneto-optical trap. The formed electronically excited RbCs* molecules correlated to the Rb(5S 1/2 ) + Cs(6P 1/2 ) dissociation limit are observed by trap loss spectroscopy. Following the decay of these excited RbCs* molecules, the formed ground state molecules are directly ionized by a two-photon single-color pulse dye laser, which is a new ionization mechanism for ground state RbCs molecules and thence detected by time-of-flight mass spectroscopy.We have produced ultracold polar RbCs molecules via photoassociation starting from laser-cooled 85 Rb and 133 Cs atoms in a dual-species, forced dark magneto-optical trap. The formed electronically excited RbCs* molecules correlated to the Rb(5S 1/2 ) + Cs(6P 1/2 ) dissociation limit are observed by trap loss spectroscopy. Following the decay of these excited RbCs* molecules, the formed ground state molecules are directly ionized by a two-photon single-color pulse dye laser, which is a new ionization mechanism for ground state RbCs molecules and thence detected by time-of-flight mass spectroscopy.

Chinese Physics LettersAug 1, 20118 citations

We report the observation of interspecies Feshbach resonances in an optically trapped mixture of

{}^{85}

Rb and

{}^{133}

Cs. We measure nine resonances in the lowest spin channel for a magnetic field range from 0 to 700 G and show that they are in good agreement with coupled-channel calculations. The interspecies background scattering length is close to zero over a large range of magnetic fields, permitting the sensitive detection of Feshbach resonances through interspecies thermalization. Our results confirm the quality of the Rb-Cs potential curves [Phys. Rev. A 85, 032506 (2012)] and offer promising starting points for the production of ultracold polar molecules.