Berlin 2014 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 14: Cold Molecules 2
MO 14.6: Vortrag
Donnerstag, 20. März 2014, 11:45–12:00, BEBEL HS213
Kolmogorov-type scaling at a non-thermal fixed point in two dimensional Bose gases — •Thorge Müller1,2, Markus Karl1,2, and Thomas Gasenzer1,2 — 1Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg — 2ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany
We present a numerical analysis of non-thermal fixed points in ultracold Bose gases in two spatial dimensions. Imprinting of multiply quantized vortices is used to drive the system far away from equilibrium. We demonstrate that the ensuing dynamical evolution leads the system towards a quasi-stationary state showing non-thermal scaling solutions in the occupation number, known as non-thermal fixed points. We provide numerical evidence that the employed driving scheme realizes a new scaling solution in the infrared, n(k) ∼ k−5. Our result has been predicted by analytical calculations, however it has not been observed numerically up to now. We discuss this solution’s connection to steady energy fluxes in the infrared regime in momentum space and to vortex clustering in real space. Also, we show that the latter leads to almost-classical superfluid flow patterns giving rise to interpret the derived scaling solution as being closely related to the Kolmogorov scaling law.