Dynamics of photoinduced collisions of cold atoms probed with picosecond laser pulses - art. no. 033421

Pump-probe experiments are performed in which cold colliding Na atoms are p hotoassociated to form Na-2. molecules, and subsequently ionized. The exper iments are performed in a regime where the pulsed photoassociation to an in termediate potential takes place at long range, and to several electronic, vibrational, and rotational states. A probe pulse then produces an ionizati on signal by further exciting these molecules to autoionizing doubly excite d states. The time dependence of the ion signal shows a dramatic flux-enhan cement effect on a nanosecond time scale due to the motion on the intermedi ate potentials. This time dependence can be viewed as monitoring the inward motion and dephasing of a population wave packet formed at long range.