Parts | Days | Selection | Search | Updates | Downloads | Help
DY: Fachverband Dynamik und Statistische Physik
DY 29: Many-body Quantum Dynamics
DY 29.7: Talk
Wednesday, April 3, 2019, 11:15–11:30, H19
Observation of universal dynamics in a spinor Bose gas far from equilibrium — •Maximilian Prüfer1, Philipp Kunkel1, Helmut Strobel1, Stefan Lannig1, Daniel Linnemann1, Christian-Marcel Schmied1, Jürgen Berges2, Thomas Gasenzer1, and Markus K. Oberthaler1 — 1Kirchhoff-Institut für Physik, Universität Heidelberg — 2Institut für Theoretische Physik, Universität Heidelberg
Far from equilibrium different scenarios on the way to equilibrium have been identified. Here, we present a new scenario featuring universal dynamics associated to the existence of non-thermal fixed points [1]. We access and study this regime experimentally for a Bose-Einstein condensate of 87Rb in the F = 1 hyperfine manifold with ferromagnetic interactions. We quench an experimental control parameter, which leads to a build-up of excitations in the transversal spin. We identify a regime in the time evolution where the in-plane orientation of this spin becomes the relevant dynamical degree of freedom. Spatially resolved read-out allows the momentum resolved study of correlation functions which show rescaling in time and space - the dynamics is solely captured by a universal scaling function and associated exponents. We experimentally identify an emergent conserved quantity which is transported towards low momentum scales. By preparing different initial conditions we confirm that the non-thermal scaling involves no fine tuning of parameters.
[1] Prüfer, M. et al., Nature 563, 217-220 (2018)