ISBN 9783868539974

978-3-86853-997-4, Reihe Physik

Ulrich Krohn
Universal scaling and coherence properties of an ultracold Rydberg gas

178 Seiten, Dissertation Universität Stuttgart (2008), Hardcover, A5

Zusammenfassung / Abstract

In summary, during the course of this work an existing experimental setup was modified in order to conduct measurements on the universal scaling behaviour as well as the coherence properties of ultracold Rydberg atoms. Universal scalings can be found in the vicinity of a second order phase transition. Here the scaling behaviour of the Rydberg excitation of ultracold atoms was investigated dependent on the interaction and the dimensionality of the density distribution of the atomic sample. In order to change the density distribution from a three dimensional to a one dimensional geometry an optical dipole trap was set up.

The coherence properties of strongly interacting ultracold Rydberg atoms have been investigated by using two different methods. For the measurements involving the rotary echo sequence a control over the phase of the excitation light was implemented to the experiment. This led to the observation of rotary echo signals, which were studied dependent on the interaction between the Rydberg atoms.

The second experiment to investigate the coherence properties of a sample of ultracold atoms that are excited into a Rydberg state involves electromagnetically induced transparency. This coherent effect in a three-level system was again studied dependent on the interaction by changing the atomic density of ground state atoms and the Rabi frequency that couples the ground state and the Rydberg state. The resulting dephasing rates of the atomic sample in the Rydberg state were investigated for the rotary echo experiments as well as for the experiments involving electromagnetically induced transparency.