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A: Fachverband Atomphysik
A 19: Ultracold Rydberg gases (jointly with Q)
A 19.1: Talk
Thursday, March 13, 2008, 08:30–08:45, 2G
Rydberg excitation of a Bose-Einstein condensate — •Ulrich Raitzsch, Rolf Heidemann, Vera Bendkowsky, Björn Butscher, Robert Löw, and Tilman Pfau — 5. Physikalisches Institut, Pfaffenwaldring 57, 70569 Stuttgart, Germany
We present our latest results on Rydberg excitation of a Bose-Einstein condensate [1]. Crossing the critical temperature Tc, a signature of the phase transition to Bose condensation is observed in the fraction of excited Rydberg atoms. The main features in the experimental data were reproduced by a simulation using a superatom model. A superatom is formed by N ground state atoms in a sphere with the blockade radius rb ∝ (C6/ℏΩ)1/6 due to the van der Waals interaction [2].
The Rydberg excitation is proven to be coherent despite strong interactions with a rotary echo technique known from nuclear magnetic resonance physics [3]. The rotary echo experiment was done for various densities of ground state atoms and excitation times, giving insight into the dephasing caused by the van der Waals interaction.
References
| 1 | R. Heidemann, et al., arXiv:0710.5622 (2007) |
| 2 | R. Heidemann, et al., Phys. Rev. Lett. 99(16), 163601(2007) |
| 3 | U. Raitzsch, et al., arXiv:0706.3869 (2007) |