Dresden 2009 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 10: Brownian motion and transport I

DY 10.6: Talk

Tuesday, March 24, 2009, 15:30–15:45, HÜL 386

Giant diffusion of active Brownian particles — •Benjamin Lindner and Ernesto M. Nicola — Max-Planck-Institute for the Physics of Complex Systems, Dresden, Germany

We study analytically the diffusion coefficient of an active Brownian particle with a spatial asymmetry. We demonstrate the existence of a critical force or, more generally, of a critical asymmetry that separates parameter regimes of giant diffusion from those with reliable directed transport. We derive a condition for the critical asymmetry by means of an exact expression for the diffusion coefficient and by a simplified discrete picture. A critical asymmetry, as predicted by the simple model, is also found in a detailed model of coupled molecular motors displaying bidirectional motion. Refs.: Lindner & Nicola Eur. Phys. J. ST 157, 43 (2008); Lindner & Nicola Phys. Rev. Lett. 101, 190603 (2008).