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DY: Fachverband Dynamik und Statistische Physik

DY 33: Brownian Motion, Stochastic Processes, Transport I

DY 33.5: Talk

Thursday, March 17, 2011, 15:00–15:15, HÜL 186

Feedback-controlled transport in an interacting colloidal system — •Ken Lichtner and Sabine H. L. Klapp — Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany

We consider a non-equilibrium system of interacting colloidal particles driven by a constant tilting force through a periodic, symmetric ”washboard” potential. As a framework for solving the equation of motion for the time-dependent density profile, we employ the Dynamical Density Functional Theory (DDFT)[1], where the microscopic particle interactions enter via a free energy functional. In [2] we demonstrate that, despite pronounced spatio-temporal correlations, the particle current can be reversed by adding suitable feedback control terms, similar to what has been found for single-particle transport[3]. We explore two distinct control protocols with time delay, focussing on either the particle positions or the density profile. Our study shows that the DDFT is an appropriate framework to implement time-delayed feedback control strategies widely used in other fields of nonlinear physics.

[1] A. J. Archer and R. Evans, J. Chem. Phys., 121 (2004) 4246.
[2] K. Lichtner and S. H. L. Klapp, Europhys. Lett., accepted.
[3] D. Hennig, Phys. Rev. E, 79 (2009) 041114.