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Published on: May 20, 2014
Diffusion of colloidal particles in a tilted periodic potential: theory versus experiment
Mykhaylo Evstigneev1, Olga Zvyagolskaya, Stefan Bleil
1Fakultät für Physik, Universität Bielefeld, 33615 Bielefeld, Germany. mykhaylo@physik.uni-bielefeld.de
Abstract:
We investigate the diffusion of a colloidal particle in a tilted periodic potential created by means of ten rotating optical tweezers arranged on a circle. Because of the viscous drag, the trap rotation leads to the onset of a tilting force in the corotating reference frame, so that in that frame the system can be described as an overdamped Brownian particle in a tilted periodic potential. The excellent agreement of the velocity and diffusion coefficient as a function of rotating frequency with theoretical predictions allowed us to extract the main parameters characterizing the system--the coefficient of free thermal diffusion and the potential corrugation depth--from the experimental results.
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