Regensburg 2007 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 30: Poster II
DY 30.1: Poster
Donnerstag, 29. März 2007, 16:00–18:00, Poster D
Giant Diffusion in many particle systems — •Olga Zvyagolskaya1, Stefan Bleil1, Peter Reimann2, and Clemens Bechinger1 — 12. Physikalisches Institut, Universität Stuttgart, Germany — 2Fakultät für Physik, Universität Bielefeld, Germany
The diffusion coefficient of a single particle in thermal equilibrium is reduced by the presence of an external (periodic) potential. When an additional constant driving force f is applied, the diffusion coefficient has been predicted to be largely enhanced and displays a maximum as a function vs. f. We have experimentally investigated this so-called giant diffusion by exposing a colloidal particle to a tilted periodic potential being created by means of optical tweezers. When measuring the diffusion coefficient with video microscopy we find good agreement with theoretical predictions. In addition to single particles, we also investigated the situation where many particles with repulsive interactions are present. We observe a strong enhancement of the diffusion coefficient as a function of the particle interaction strength for constant potential depth and driving force. In addition we observe the diffusion coefficient to depend on the ratio of particles and potential minima in the system.
P. Reimann, C. Van den Broeck, H. Linke, P. Hänggi, J.M. Rubi, and A. Pérez-Madrid; PRL 87, 010602 (2006)