Optimized production of ultracold ground-state molecules: Stabilization employing potentials with ion-pair character and strong spin-orbit coupling

摘要

We discuss the production of ultracold molecules in their electronic groundstate by photoassociation employing electronically excited states with ion-paircharacter and strong spin-orbit interaction. A short photoassociation laserpulse drives a non-resonant three-photon transition for alkali atoms collidingin their lowest triplet state. The excited state wave packet is transferred tothe ground electronic state by a second laser pulse, driving a resonanttwo-photon transition. After analyzing the transition matrix elements governingthe stabilization step, we discuss the efficiency of population transfer usingtransform-limited and linearly chirped laser pulses. Finally, we employ optimalcontrol theory to find the most efficient stabilization pathways. We find thatthe stabilization efficiency can be increased by one and two orders ofmagnitude for linearly chirped and optimally shaped laser pulses, respectively.