Dual-species stimulated deceleration of MgF molecules with Rb atoms

We propose a scheme for dual-species deceleration and trapping of a cold atom–molecule mixture by a frequency chirping stimulated force. We study the stimulated force exerted on MgF and Rb using optical Bloch equations based on a direct numerical solution for the time-dependent density matrix. We analyze the relationship between the frequency chirping rate and the number of MgF molecules and Rb atoms. In addition, we study the dynamical process of molecular deceleration and the effect of transverse diffusion. Monte–Carlo simulations show that buffer-gas-cooled MgF and Rb beams, with initial velocities of 200 m/s and 130 m/s respectively, can be decelerated to less than 10 m/s. This is achieved with laser powers of as low as 357 mW for MgF and 10 mW for Rb per traveling wave. The rapid deceleration minimizes molecular loss due to transverse diffusion during the deceleration process. The estimated number of molecules that can be trapped in a magneto-optical trap (MOT) is about 9.0 × 10⁶, which is an order of magnitude larger than the number of MgF molecules decelerated by the spontaneous radiation force. The results offer a promising starting point for further studies of sympathetic cooling.