Photoassociation of Sr 84 n 1 D 2 ultralong-range Rydberg dimers

Measurements of the production of 5 s n d 1 D 2 – 5 s 2 1 S 0 ultralong-range Rydberg dimers through photoassocation in an ultracold Sr 84 atomic gas are reported. The molecular potential associated with the Rydberg D state is anisotropic and the molecular states are characterized by the vibrational quantum number ν and the total angular momentum K ⃗ = L ⃗ + N ⃗ , where L ⃗ and N ⃗ are the electronic orbital angular momentum and rotational angular momentum, respectively. The measured molecular binding energies agree reasonably well with theoretical predictions. Additionally, the electron-atom scattering leads to broader line shapes in the photoassociation spectrum than might be expected simply from the angular momentum of the initial colliding cold-atom pairs.