title: Emergence of coherence and the dynamics of quantum phase transitions.
abstract: The dynamics of quantum phase transitions pose one of the most challenging problems in modern many-body physics. Here, we study a prototypical example in a clean and well-controlled ultracold atom setup by observing the emergence of coherence when crossing the Mott insulator to superfluid quantum phase transition. In the 1D Bose-Hubbard model, we find perfect agreement between experimental observations and numerical simulations for the resulting coherence length. We, thereby, perform a largely certified analog quantum simulation of this strongly correlated system reaching beyond the regime of free quasiparticles. Experimentally, we additionally explore the emergence of coherence in higher dimensions, where no classical simulations are available, as well as for negative temperatures. For intermediate quench velocities, we observe a power-law behavior of the coherence length, reminiscent of the Kibble-Zurek mechanism. However, we find nonuniversal exponents that cannot be captured by this mechanism or any other known model.
authors.affiliation: Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 Munich, Germany; Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany;
authors.forename: Simon
authors.initials: S
authors.lastname: Braun
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany;
authors.forename: Mathis
authors.initials: M
authors.lastname: Friesdorf
authors.affiliation: Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 Munich, Germany; Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany;
authors.forename: Sean S
authors.initials: SS
authors.lastname: Hodgman
authors.affiliation: Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 Munich, Germany; Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany;
authors.forename: Michael
authors.initials: M
authors.lastname: Schreiber
authors.affiliation: Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 Munich, Germany; Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany;
authors.forename: Jens Philipp
authors.initials: JP
authors.lastname: Ronzheimer
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany; Max-Planck-Institut für Gravitationsphysik, 14476 Potsdam-Golm, Germany; and.
authors.forename: Arnau
authors.initials: A
authors.lastname: Riera
authors.affiliation: Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain.
authors.forename: Marco
authors.initials: M
authors.lastname: Del Rey
authors.affiliation: Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 Munich, Germany; Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany;
authors.forename: Immanuel
authors.initials: I
authors.lastname: Bloch
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany;
authors.forename: Jens
authors.initials: J
authors.lastname: Eisert
authors.affiliation: Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 Munich, Germany; Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany; ulrich.schneider@lmu.de.
authors.forename: Ulrich
authors.identifier: http://orcid.org/0000-0003-4345-9498
authors.initials: U
authors.lastname: Schneider
keywords: Mott insulator; nonequilibrium dynamics; optical lattice; quantum simulation; ultracold atoms