Hannover 2016 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 29: Quantum Gases: Bosons III

Q 29.1: Gruppenbericht

Mittwoch, 2. März 2016, 11:00–11:30, e001

BEC Heidelberg: Exploring non-linear dynamics - from discrete to continuous — •Philipp Kunkel, Maximilian Prüfer, Daniel Linnemann, Helmut Strobel, Wolfgang Müssel, Christian-Marcel Schmied, Thomas Gasenzer, and Markus K. Oberthaler — Kirchhoff-Institut für Physik, Im Neuenheimer Feld 227, 69120 Heidelberg

Spinor Bose-Einstein condensates are ideally suited to study complex many-particle dynamics, as they offer a unique level of experimental control. Our experiments focus on spin-mixing as the non-linear mechanism coupling internal and external degrees of freedom. We study this interplay using spin-changing collisions in Rb-87 in quasi one-dimensional confinement in two different regimes. By tuning the longitudinal trap frequency we first generate a situation of only few accessible modes. In this situation the spin-changing collisions act on top of an effective potential. We use spin-mixing as a tool to probe this potential and experimentally observe the population of different spatial modes. The possibility of creating nonlocal entanglement in this controlled few spatial modes situation is investigated. Going into the continuous regime, Bogoliubov theory predicts unstable momentum modes, which are occupied due to the local creation of atom pairs with opposite momenta. Experimentally we find strong spatial correlations for short evolution times. For later times, irrespective of different initial conditions the dynamics are governed by many modes but nevertheless general features can be found. We identify emerging, long living structures correlating the collective spin and the total density.