Hannover 2010 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 3: Quantum Gases: Bosons I

Q 3.7: Talk

Monday, March 8, 2010, 15:30–15:45, E 001

Local and non-local relaxation of a 1D Bose gas with finite interactions — •Dominik Muth, Bernd Schmidt, and Michael Fleischhauer — Fachbereich Physik und Forschugszentrum OPTIMAS, Technische Universität Kaiserslautern

Simulating the dynamics of interacting quantum many-body systems is one of the computationally hardest problems in physics. One of the open questions is, whether integrable models, which have an infinite number of conserved quantities, relax (say, after a quench in the interaction strength) to a state that can be locally fully described by a grand canonical ensemble, defined only by temperature and chemical potential, or whether other quantities have to be taken into account in the Gibbs state. We investigate this question in the case of a 1D Bose gas with repulsive delta-type interactions, as found in recent experiments using ultra-cold gases. Dynamical simulations (employing a matrix-product-states description) of a quench yields both local and non-local correlations. They indicate, that indeed the stationary state for local quantities is identical to the grand canonical one. The same method is applied to the regime of strong attractive interactions. Here experiments have shown, that the system, instead of collapsing into the ground state, remains in a highly excited, metastable state. The properties and process of the formation of this so called super Tonks-Girardeau gas will be explored.