Photoassociative creation of ultracold heteronuclear 6Li40K* molecules
Laboratoire Kastler Brossel, École Normale Supérieure, CNRS, Université Pierre et Marie-Curie 24 rue Lhomond, F-75231 Paris Cedex 05, France, EU
2 Laboratoire Aimé Cotton, CNRS, Université Paris-Sud 11 - F-91405 Orsay, France, EU
Accepted: 7 September 2011
We investigate the formation of weakly bound, electronically excited, heteronuclear 6Li40K* molecules by single-photon photoassociation in a magneto-optical trap. We performed trap loss spectroscopy within a range of 325 GHz below the Li(2S1/2)+K(4P3/2) and Li(2S1/2)+K(4P1/2) asymptotic states and observed more than 60 resonances, which we identify as rovibrational levels of 7 of 8 attractive long-range molecular potentials. The long-range dispersion coefficients and rotational constants are derived. We find large molecule formation rates of up to ∼3.5×107s− 1, which are shown to be comparable to those for homonuclear 40K2*. Using a theoretical model we infer decay rates to the deeply bound electronic ground-state vibrational level X1Σ+(v′ =3) of ∼5×104 s−1. Our results pave the way for the production of ultracold bosonic ground-state 6Li40K molecules which exhibit a large intrinsic permanent electric dipole moment.
PACS: 33.20.-t – Molecular spectra / 37.10.Mn – Slowing and cooling of molecules / 34.20.Cf – Interatomic potentials and forces
© EPLA, 2011