Pulse sequences in photoassociation via adiabatic passage

Abstract

We perform a detailed study of pulse sequences in a photoassociation via adiabatic passage (PAP) process to transfer population from an ensemble of ultracold atomic clouds to a vibrationally cold molecular state. We show that an appreciable final population of ultracold NaCs molecules can be achieved with optimized pulses in either the 'counter-intuitive' (t P > t S) or 'intuitive' (t P < t S) PAP pulse sequences, with t P and t S denoting the temporal centers of the pump and Stokes pulses, respectively. By investigating the dependence of the reactive yield on pulse sequences, in a wide range of t P-t S, we show that there is not a fundamental preference to either pulse sequence in a PAP process. We explain this no-sequence-preference phenomenon by analyzing a multi-bound model so that an analogy can be drawn to the conventional stimulated Raman adiabatic passage. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.