Diffusion of colloidal particles in a tilted periodic potential: theory versus experiment.
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.
Fakultät für Physik, Universität Bielefeld, 33615 Bielefeld, Germany. mykhaylo@physik.uni-bielefeld.de
Mykhaylo
M
Evstigneev
Olga
O
Zvyagolskaya
Stefan
S
Bleil
Ralf
R
Eichhorn
Clemens
C
Bechinger
Peter
P
Reimann