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DY: Fachverband Dynamik und Statistische Physik

DY 10: Brownian motion and transport I

DY 10.3: Vortrag

Dienstag, 24. März 2009, 14:45–15:00, HÜL 386

Brownian motion in confined geometries – the role of entropic barriers — •Gerhard Schmid, P. Sekhar Burada, and Peter Hänggi — Institut für Physik, Universität Augsburg, D-86135 Augsburg

For particles undergoing biased Brownian motion in static media enclosed by confining geometries, transport exhibits intriguing features such as (i) a decrease of nonlinear mobility with increasing temperature or, also, (ii) a broad excess peak of the effective diffusion above the free diffusion limit [1,2]. These paradoxical aspects can be understood in terms of entropic contributions resulting from the restricted dynamics in phase space. Accordingly, bottlenecks result in entropic barriers which, however, exhibit a distinct temperature behavior from that observed for energetic barriers. The use of a time-dependent driving then causes Stochastic Resonance, thus demonstrating an anomalous signal amplification in systems possessing entropic barriers [3].

[1] D. Reguera, G. Schmid, P. S. Burada, J. M. Rubi, P. Reimann, and P. Hänggi, Phys. Rev. Lett. 96, 130603 (2006).

[2] P. S. Burada, P. Hänggi, F. Marchesoni, G. Schmid and P. Talkner, ChemPhysChem (2009), DOI: 10.1002/cphc.200800526.

[3] P. S. Burada, G. Schmid, D. Reguera, M. H. Vainstein, J. M. Rubi, and P. Hänggi, Phys. Rev. Lett. 101, 130602 (2008).