title: Experimental observation of a generalized Gibbs ensemble.
abstract: The description of the non-equilibrium dynamics of isolated quantum many-body systems within the framework of statistical mechanics is a fundamental open question. Conventional thermodynamical ensembles fail to describe the large class of systems that exhibit nontrivial conserved quantities, and generalized ensembles have been predicted to maximize entropy in these systems. We show experimentally that a degenerate one-dimensional Bose gas relaxes to a state that can be described by such a generalized ensemble. This is verified through a detailed study of correlation functions up to 10th order. The applicability of the generalized ensemble description for isolated quantum many-body systems points to a natural emergence of classical statistical properties from the microscopic unitary quantum evolution.
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria.
authors: Tim
authors: T
authors: Langen
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria. Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany. ExtreMe Matter Institute (EMMI), GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
authors: Sebastian
authors: S
authors: Erne
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria.
authors: Remi
authors: R
authors: Geiger
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria.
authors: Bernhard
authors: B
authors: Rauer
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria.
authors: Thomas
authors: T
authors: Schweigler
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria.
authors: Maximilian
authors: M
authors: Kuhnert
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria.
authors: Wolfgang
authors: W
authors: Rohringer
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria. Wolfgang Pauli Institute, 1090 Vienna, Austria. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia.
authors: Igor E
authors: IE
authors: Mazets
authors: Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany. ExtreMe Matter Institute (EMMI), GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
authors: Thomas
authors: T
authors: Gasenzer
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria. schmiedmayer@atomchip.org.
authors: Jörg
authors: J
authors: Schmiedmayer