Abstract
We theoretically explore photoassociation by adiabatic passage of two colliding cold atoms in an atomic trap to form an ultracold molecule. We consider the incoherent thermal nature of the scattering process in a trap and show that coherent manipulations of the atomic ensemble, such as adiabatic passage, are feasible if performed within the coherence time window dictated by the temperature, which is relatively long for cold atoms. We show that a sequence of pulses of moderate intensities, each lasting , can photoassociate a large fraction of the atomic ensemble at temperature of and density of . Use of multiple pulse sequences makes it possible to populate the ground vibrational state. Employing spontaneous decay from a selected excited state, one can accumulate the molecules in a narrow distribution of vibrational states in the ground electronic potential. Alternatively, by removing the created molecules from the beam path between pulse sets, one can create a low-density ensemble of molecules in their ground rovibrational state.
1 More- Received 16 May 2006
DOI:https://doi.org/10.1103/PhysRevA.75.013405
©2007 American Physical Society