Eur. Phys. J. D 65, 113-123 (2011)
https://doi.org/10.1140/epjd/e2011-20083-6

Regular Article

Cold atom-molecule photoassociation: long-range interactions beyond the 1/Rⁿ expansion

Laboratoire Aimé Cotton, CNRS, Bât. 505, Univ. Paris-Sud, 91405 Orsay Cedex, France

^a e-mail: maxence.lepers@u-psud.fr

Received: 31 January 2011
Received in final form: 28 February 2011
Published online: 17 May 2011

Abstract

We investigate theoretically the combination of first-order quadrupole-quadrupole and second-order dipole-dipole effects on the long-range electrostatic interactions between a ground-state homonuclear alkali-metal dimer and an excited alkali-metal atom. As the electrostatic energy is comparable to the dimer rotational structure, we develop a general description of the long-range interactions in the framework of the second-order degenerate perturbation theory, which allows for couplings between the dimer rotational levels. The resulting adiabatic potential energy curves exhibit avoided crossings, and cannot be expanded as the usual 1/Rⁿ series. We study in details the particular case Cs₂+Cs(6²P). Our results are found promising to achieve photoassociation of ultracold trimers.