Regensburg 2010 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 13: Granular Matter/ Contact Dynamics II
DY 13.2: Vortrag
Mittwoch, 24. März 2010, 10:00–10:15, H47
Glass-Transition for Dissipative Systems under Driving — •Till Kranz1,2, Matthias Sperl1,3, and Annette Zippelius1,2 — 1Institut für Theoretische Physik, Universität Göttingen — 2MPI für Dynamik und Selbstorganisation, Göttingen — 3Institut für Materialphysik im Weltraum, DLR Köln
In order to reach a steady state, granular (dissipative) systems need an external driving. One of the many possible methods is to fluidise the system by a fluctuating driving force. We extend the equilibrium mode coupling theory (MCT) of molecular fluids [1] to the steady state of such a randomly driven granular fluid. This allows us to calculate the coherent scattering function Φ(q, t) = ⟨ρq(0)|ρq(t)⟩. We observe a mode coupling glass transition for all dissipation strengths characterized by a constant coefficient of normal restitution є. The critical density ϕc increases with increasing dissipation. Close to the critical density we predict a two step relaxation of dynamical correlation functions. Both the plateau height fq as well as the critical exponents differ from those found for equilibrium glass-formers.
[1] W. Götze, Complex Dynamics of Glass-Forming Liquids: A Mode-Coupling Theory, (Oxford University Press, 2009)