Controlling Quantum Rotation With Light

Semiclassical catastrophes in the dynamics of a quantum rotor (molecule) driven by a strong time-varying field are considered. We show that for strong enough fields, a sharp peak in the rotor angular distribution can be achieved via time-domain focusing phenomenon, followed by the formation of angular rainbows and glory-like angular structures. Several scenarios leading to the enhanced angular squeezing are proposed that use specially designed and optimized sequences of pulses. The predicted effects can be observed in many processes, ranging from molecular alignment (orientation) by laser fields to heavy-ion collisions, and the squeezing of cold atoms in a pulsed optical lattice.Comment: 8 pages, Latex, 8 figures, based on the talk given at the Eighth Rochester Conference on Coherence and Quantum Optics (June 13-16, 2001). To appear in the proceedings of CQO8 (Plenum, 2002