Coherent control of ultracold Rydberg gases
Dr. Robert Löw (5. Physikalisches Institut, Universität Stuttgart)

Rydberg atoms exhibit strong interactions which are effective over a distance of many microns. If now an ensemble of ultracold atoms with a typical interparticle spacing of below one micron is excited to Rydberg states a strongly interacting gas emerges. By coherent excitation it is possible to enter a regime of strong quantum correlations. The observation of a universal scaling behaviour is a strong indication for the existence of a quatum critical point. In the second part I will report on the coherent excitation of ultra-longrange Rydberg molecules. Here the highly excited electron of the Rydberg atom "catches" a close by ground state atom and establishes a homonuclear dimer with large internuclear separation.