Intracollisional interference in resonant collisions of Na Rydberg atoms

Abstract

The theory of resonant dipole-dipole energy transfer in an electric field E indicates substantial differences between the collision velocities v\ensuremath{\parallel}E and v\ensuremath{\perp}E. For v\ensuremath{\parallel}E the cross section vanishes at exact resonance due to a destructive interference in the transition amplitude, producing a double-peaked line shape. The presence of the permanent dipole moments in the field produces slight shifts and asymmetries of the collisional resonance line shapes. A high-resolution experimental study of the cases v\ensuremath{\parallel}E and v\ensuremath{\perp}E indicates that the theoretical predictions are correct and further allows the resolution of the spin-orbit structure in the resonant collisions.