Asymptotic analysis of mode-coupling theory of active nonlinear microrheology

Manuel Gnann and Thomas Voigtmann

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Submission date: 10. Apr. 2012 (revised version: April 2012)
Pages: 19
published in: Physical review / E, 86 (2012) 1, art-no. 011406 
DOI number (of the published article): 10.1103/PhysRevE.86.011406
Bibtex
PACS-Numbers: 82.70.-y, 64.70.pv, 83.10.-y
Keywords and phrases: Colloidal dispersions, suspensions, and aggregates
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Abstract:
We discuss a schematic model of mode-coupling theory for force-driven active nonlinear microrheology, where a single probe particle is pulled by a constant external force through a dense host medium. The model exhibits both a glass transition for the host, and a force-induced delocalization transition, where an initially localized probe inside the glassy host attains a nonvanishing steadystate velocity by locally melting the glass. Asymptotic expressions for the transient correlation functions of the schematic model are derived, valid close to the transition points. There appear several nontrivial time scales relevant for the decay laws of the correlator. For the nonlinear friction coecient of the probe, the asymptotic expressions give rise to two-parameter scaling laws.