Hannover 2010 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 21: Poster I
Q 21.26: Poster
Dienstag, 9. März 2010, 16:00–19:00, Lichthof
Ionization dynamics and antiblockade of an ultracold Ryd-berggas — •Nele Müller1, Thomas Amthor1, Christoph S. Hofmann1, Georg Günter1, Hanna Schempp1, Christian Giese2, and Matthias Weidemüller1 — 1Physikalisches Institut, Universität Heidelberg, Philosophenweg 12, 69120 Heidelberg — 2Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg
Using time-resolved spectroscopic measurements of the Penning ionization signal we are able to identify slight variations in the Rydberg pair distribution of randomly arranged ultracold atoms. For attractive interaction potentials, atoms excited to Rydberg states on the red-detuned wing of the resonance are observed to ionize first. In this case pairs of atoms with small separation are excited and these experience strong attractive forces[1]. This approach can also be applied to repulsively interacting Rydberg states, where atoms excited on the blue-detuned wing of the resonance ionize faster[2]. We further extend this method by using Autler-Townes-splittings to achieve specific detunings to match the coupling energy of one optical transition to the interaction energy of the long-range Rydberg interactions. Hence, the otherwise blocked excitation of close pairs becomes feasible (antiblockade)[3]. Our experimental results agree well with a pair interaction model[4].
[1] T. Amthor et al., Phys. Rev. Lett 98, 023004 (2007)
[2] T. Amthor et al., Phys. Rev. A 76, 054702 (2007)
[3] C. Ates et al., Phys. Rev. Lett. 98, 023002 (2007)
[4] T. Amthor et al., arXiv:0909.0837v1