Mainz 2017 – scientific programme

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MO: Fachverband Molekülphysik

MO 9: Posters 1: Dichroism, VUV and Xray, Clusters, and Cold Molecules

MO 9.20: Poster

Tuesday, March 7, 2017, 17:00–19:00, P OG1

Controlling Cold Atom-ion Collisions Using Rydberg States — •Limei Wang, Markus Deiss, and Johannes Hecker Denschlag — Inst. f. Quantenmaterie, Universität Ulm

We propose a scheme where the cold collision between an ultracold Rb atom and a trapped single Ba⁺ ion will be controlled by a ’blue shielding laser’. During the collision, the laser excites the Rb atom to a repulsive electronically excited molecular state formed by the Rydberg atom and ion once the atom approaches to a certain internuclear distance. In this way the ion is effectively surrounded by a hard potential wall that the atom cannot cross. Once the atom leaves the interaction area, it is de-excited back in an adiabatic way to its original level. By controlling the laser power and the laser frequency, as well as by addressing different Rydberg states, the properties of this ’shielding’ can be widely tuned. Long-range shielding effects are expected to be realized with higher n Rydberg states.

An important application of the collision control is to suppress unwanted chemical reactions between atoms and ion, such as charge exchange or three-body recombination. The suppression of inelastic collisions is an essential tool required for the young developing field of cold atom-ion hybrid systems where in general only elastic collisions are desired.