Ultracold atom-molecule conversion dynamics in a closed-loop three-level system

The production of ultracold molecules is one of the most exciting topics in the field of ultracold physics, which has important theoretical values and broad application prospects. We propose an ultracold atom-molecule conversion model in a closed-loop three-level system based on three available transitions, in which the population dynamics depends on three coupling fields and global phase. We investigate the atom-molecule conversion dynamics in the closed-loop three-level system. We show the distribution of population on excited molecular state and ground molecular state with arbitrary proportion can be achieved by adjusting pulse amplitudes of the external fields properly. We also explore the effects of time delay, pulse width and global phase on the conversion process. The results show that, by tuning these parameters, the stable atom-molecule conversion with arbitrary proportion can be realized. (C) 2021 Elsevier B.V. All rights reserved.