Heidelberg 2015 – wissenschaftliches Programm
A 36.7: Poster
Donnerstag, 26. März 2015, 17:00–19:00, C/Foyer
Long-range Rydberg molecules – Rydberg-Rydberg and Rydberg–ground-state interactions — •Johannes Deiglmayr, Heiner Saßmannshausen, and Frédéric Merkt — Laboratory of Physical Chemistry, ETH Zürich, Switzerland
We report on two recent observations in our experiments with ultracold Cs atoms . First, we discuss the observation of dipole-quadrupole interactions between two Rydberg atoms. Because the dipole-quadrupole interaction does not conserve the electronic parity, the conservation of total parity requires that the excitation of dipole-quadrupole-coupled pair states in our experiments  is accompanied by an entanglement of electronic and rotational motions of the atom pair, which is facilitated by the near-degeneracy of even- and odd-L partial waves.
Second, we report on the experimental characterization of singlet-scattering channels in long-range Rydberg molecules composed of a Rydberg and a ground-state atom. We observe the formation of such molecules by photoassociation spectroscopy near np3/2 resonances (n=26-34). The spectra reveal two types of molecular states recently predicted by Anderson et al. [PRL 112, 163201 (2014)]: Deeply bound pure triplet states and more weakly bound states with mixed singlet and triplet character. The experimental observations are well described by a model including s-wave scattering, the hyperfine interaction of the ground-state atom and the fine-structure of the Rydberg atom.
 H. Saßmannshausen, F. Merkt, J. Deiglmayr, PRA 87, 032519 (2013);  J. Deiglmayr, H. Saßmannshausen, P. Pillet, and F. Merkt, PRL 113, 193001 (2014)