Coherent photoassociation of a quantum degenerate gas

Summary form only given. Coherence is predicted to be absent for the case of a non-degenerate thermal gas. Little has been said, however, about the photoassociation of the thermal component of a quantum degenerate gas. In the present work, we have proven that, under favorable experimental conditions, it is possible to establish three-level coherence in two-photon association for this later case. An ultracold (T - 280 nK) sample of about 10/sup 5/ spin-polarized /sup 7/Li atoms was probed with a pulse consisting of two co-propagating laser beams.