Berlin 2014 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 32: Poster: Quantum gases, ultracold atoms and molecules
Q 32.4: Poster
Mittwoch, 19. März 2014, 16:30–18:30, Spree-Palais
Non-thermal fixed points and strong wave-turbulence in a dilute Bose gas — •Isara Chantesana1,2 and Thomas Gasenzer1,2 — 1Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany — 2ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany
Far-from equilibrium dynamics of a dilute Bose gas is studied by means of the two-particle irreducible action formalism. We investigate the properties of non-thermal fixed points predicted previously, which are related to non-perturbative strong wave turbulence solutions of the many-body dynamic equations. According to these predictions, the occupation number spectrum shows two alternative new scaling laws in the low-momentum regime, as a consequence of a non-perturbative scaling of the coupling parameter caused by many-body effects. We study this scaling in view of integrability constraints in order to clarify whether the non-thermal fixed point has Gaussian character. This question is of central interest for the development of a renormalisation-group description of far-from-equilibrium critical phenomena.