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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 Kranz^1,2, Matthias Sperl^1,3, and Annette Zippelius^1,2 — 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) = ⟨ρ_q(0)|ρ_q(t)⟩. We observe a mode coupling glass transition for all dissipation strengths characterized by a constant coefficient of normal restitution є. The critical density ϕ_c increases with increasing dissipation. Close to the critical density we predict a two step relaxation of dynamical correlation functions. Both the plateau height f_q 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)