Dresden 2006 – scientific programme

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DY: Dynamik und Statistische Physik

DY 24: Brownian Motion and Kinetic Theory I

DY 24.5: Talk

Tuesday, March 28, 2006, 15:30–15:45, H\"UL 186

Entropic transport in symmetric tubes — •Poornachandra S. Burada, Gerhard Schmid, and Peter Hänggi — Institut für Physik, Universität Augsburg

We study the transport of biased Brownian particles in symmetric tubes in two and three dimensions with periodically varying cross-section. Bottlenecks which produce entropic barriers hinder the motion of the particles and exhibit peculiar characteristics in the transport behavior which are different from that taking place in systems with energy barriers [1]. The constrained dynamics is responsible for an existence of a scaling regime for the particle current and the diffusion coefficient in terms of the ratio between the work done to the particles and thermal energy. Our findings, genuine of the entropic nature of the barriers, can be used in the control of transport through quasi-one dimensional structures, such as pores, ion channels and zeolites, in which irregularities of the boundaries may induce entropic effects. The kinetic description of the dynamic quantities have been developed within an analytic approach [2] and corroborated by simulations.

[1] P. Reimann, C. Van den Broeck, H. Linke, P. Hänggi, J.M. Rubi, and   A. Pérez-Madrid Phys. Rev. Lett. 87, 010602 (2001).

[2] D. Reguera and J.M. Rubi, Phys. Rev. E 64, 061106 (2001).