Hamburg 2009 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 56: Poster IV

Q 56.2: Poster

Thursday, March 5, 2009, 16:30–19:00, VMP 9 Poster

Non-thermal fixed points in an ultracold Bose gas far from equilibrium — •Christian Scheppach and Thomas Gasenzer — Institut für Theoretische Physik, Philosophenweg 16, D-69120 Heidelberg

The dynamics of a relativistic N-component scalar quantum field theory is known to exhibit fixed points far from thermal equilibrium characterised by anomalously large critical exponents. The two-particle-irreducible (2PI) effective action in next-to-leading order of a 1/N expansion, a non-perturbative approximation scheme suitable for far-from-equilibrium dynamics, allows to calculate analytically the critical exponents. We investigate such non-thermal fixed points and the associated critical exponents in a non-relativistic quantum field theory describing an ultracold Bose gas and discuss possibilities to observe them in experiment. Ultracold quantum gases are under very good experimental control and hence provide the possibility to gain access to many-body dynamical phenomena far from equilibrium and to test results from non-perturbative quantum field theory in experiment.