Optical control of collisional population flow between molecular electronic states of different spin multiplicity

In this work we demonstrate optical control of the singlet-triplet probability distribution in the outcome of a collisional process involving lithium dimers and argon atoms. The control is achieved using the Autler-Townes effect to manipulate the spin character of a spin-orbit coupled pair of levels serving as a “gateway” between the singlet and triplet electronic state manifolds.