Dresden 2011 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 41: Brownian Motion, Stochastic Processes, Transport II

DY 41.3: Vortrag

Freitag, 18. März 2011, 10:45–11:00, HÜL 186

Asymmetric Brownian Particles — •Martin Reichelsdorfer and Klaus Mecke — Institut für Theoretische Physik, Universität Erlangen-Nürnberg, Staudstr. 7, 91058 Erlangen

We study the influence of the shape of Brownian particles on their dynamics. Under nonequilibrium conditions, asymmetric particles are found to be able to conduct directed average motion. A simple generic three-state model is proposed, which already exhibits crucial features and which reveals how the system relaxes to equilibrium from a symmetric nonequilibrium velocity distribution through asymmetric intermediate states. However, the differences in the behaviour of symmetric and asymmetric particles are not restricted to nonequilibrium. For instance, additional time-scales appear in the equilibrium velocity auto-correlation function and the latter may now also oscillate and adopt negative values.

In terms of an application, asymmetric Brownian particles can be used for constructing molecular motors that work even in spatially symmetric environments (e.g., no temperature gradients, no tilted or asymmetric potentials). Inspired by biology, we present a model where nonequilibrium is sustained by periodically stopping the motor at binding sites along a rail.