Prospects for production of ultracold $\mathsf{X^{1}\Sigma^{ + }}$ RbCs molecules

Abstract

Recently, we have reported photoassociation of laser-cooled Rb and Cs atoms, decay of the RbCs photoassociation resonances to high levels of the $a^{3}\Sigma^{ + }$ state, and reexcitation to vibronic levels of the $c (2)^{3}\Sigma^{ + }$ state [Kerman et al. , Phys. Rev. Lett. 92, 033004; 153001 (2004)]. Considering the reexcitation spectrum, we report here a preliminary analysis of perturbations in the c state by high levels of the $b^{3}\Pi$ and low levels of the $B^{1}\Pi$ state. Mixing with the B state provides the singlet character needed to stimulate decay to v = 0 of the $X^{1}\Sigma^{ + }$ ground state. We conclude that an experimental procedure that involves photoassociation of laser-cooled atoms, radiative decay, and stimulated Raman transfer to the ground electronic state is a feasible method for producing translationally, rotationally, vibrationally and electronically cold RbCs molecules.