Düsseldorf 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
Q: Fachverband Quantenoptik und Photonik
Q 5: Quantengase (Bose-Einstein-Kondensation)
Q 5.5: Vortrag
Montag, 19. März 2007, 15:15–15:30, 6J
Quantum vs. Classical Dynamics of an Ultracold Bose Gas — •Thomas Gasenzer1 and Jürgen Berges2 — 1Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg — 2Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, 64289 Darmstadt
Dynamics of an ultracold gas far from thermal equilibrium is studied with special focus on the quantum vs. the classical statistical aspects of the many-body time evolution. Knowledge about the differences between quantum and classical statistical dynamics is of particular interest for experimental and theoretical efforts to identify effects of quantum fluctuations. The employed functional-integral approach, which involves the two-particle irreducible (2PI) effective action, allows in a particularly transparent way to distinguish between the time evolution of correlation functions in the classical and quantum cases, respectively. It is shown that these cases only differ in the interaction vertices appearing in the phase factor in the generating functional. The differences in the dynamic equations beyond the purely classical Hartree-Fock-Bogoliubov mean-field theory are derived in next-to-leading order of the 2PI 1/ N approximation.