Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DY: Fachverband Dynamik und Statistische Physik
DY 35: Brownian Motion and Transport
DY 35.1: Vortrag
Freitag, 15. März 2013, 09:30–09:45, H48
Two-dimensional transport of paramagnetic colloids via an AC-induced ratchet — •Robert Gernert and Sabine H. L. Klapp — Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin
Magnetic garnet films are characterized by a striped magnetisation which can be adjusted through an external homogeneous magnetic field. An oscillating field drives paramagnetic colloids, which perform Brownian motion in a plane above the film, out of equilibrium and induces a ratchet effect.1 2 We investigate the dependence of the arising transport on particle interaction. The Gaussian core model is used to define the interaction potential.
The Brownian motion is assumed to be overdamped. As a framework for solving the equation of motion for the time-dependent probability density, we employ the Dynamical Density Functional Theory (DDFT) where the microscopic particle interactions enter via a free energy functional.3
Mean squared displacement, diffusion coefficient and other transport properties are calculated in two dimensions and in a one-dimensional cut perpendicular to the stripes of magnetisation. First results of simulations including attractive magnetic dipole interactions are shown.
1 P. Tierno, F. Sagues, T. H. Johansen and T. M. Fischer, Phys. Chem. Chem. Phys. 11, 9615 (2009)
2 A. Fortini and M. Schmidt, Phys. Rev. E 83, 041411 (2011)
3 A. J. Archer and R. Evans, J. Chem. Phys. 121, 4246 (2004)