Research

Ultracold coherent dynamics of matter has become experimentally accessible with trapping techniques and the creation of Bose Einstein Condensates, with thousands of atoms represented by a single quantum state. As in the ultrafast our primary interest is devoted to excitation dynamics. Rydberg excitations go particlularly well along with ultracold matter since the (fragile) large Rydberg orbits survive for a long time in an ultracold environment which also is suitable to distinguish tiny energy differences between Rydberg levels.
Peculiar large Rydberg molecules can form, and the ultrastrong interaction of Rydberg atoms leads to strongly correlated gases interesting for condensed matter and to excitonic Rydberg dynamics entangling coherently atomic and eletronic motion which represents a new kind of Rydberg chemistry. The latter is particularly interesting since it can serve as laboratory to study dynamics relevant for light harvesting and even more fundamental molecular mechanisms such as conical intersections as we have shown. Moreover, Rydberg aggregates are a natural probe for coherence and can be coupled in a controlled way to different environments in order to get a better understanding of the different decoherence mechanisms. This also includes the coupling to nano-mechanical devices.

Rydberg Molecules . Excitonic Rydberg dynamics . Optomechanical Rydberg Physics