Universal stereodynamics and electric field control of cold atom-molecule collisions

We use numerically exact quantum dynamics calculations to demonstrate universal stereoselectivity of cold atom-molecule collisions in an external electric field. We show that cold collisions of Ne atoms with OH molecules in their low-field-seeking f-states, whose dipole moments are oriented against the field direction, are much more likely to lead to inelastic scattering than those of molecules oriented along the field direction, causing nearly perfect steric asymmetry in the inelastic collision cross sections [1]. We identify the universal nature of this effect as due to the threshold suppression of inelastic scattering between the degenerate Stark M-sublevels of the high-field-seeking e-state, where M is the projection of the total angular momentum of the molecule on the field axis. Above the Lambda-doublet threshold, the stereodynamics of inelastic atom-molecule collisions can be tuned via electric-field-induced resonances, which enable effective control of Ne+OH scattering over the range of collision energies achievable in current merged beam experiments.