Berlin 2012 – scientific programme
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BP: Fachverband Biologische Physik
BP 18: Posters: Statistical Physics in Biological Systems
BP 18.11: Poster
Wednesday, March 28, 2012, 17:30–19:30, Poster A
Directed Transport of Confined Brownian Particles with Torque — •Paul Radtke and Lutz Schimansky-Geier — Institute of Physics, Humboldt University at Berlin, Newtonstr. 15, D-12489 Berlin, Germany
We consider the motion of Brownian particles who are confined in tunnel with differently shaped walls. The particles are driven by random fluctuations modeled by the Ornstein-Uhlenbeck process with given correlation time τc. It is implemented as both a thermal and nonthermal process. Furthermore, the particles’ trajectories possess a nonzero mean curvature.
We investigate numerically whether the particles diffuse symmetrically in both directions, or a net transport into one direction emerges. In this case our setup realizes a ratchet mechanism; random fluctuations in the thermodynamic nonequilibrium are rectified. For the nonthermal noise we find the emergence of transport. It is investigated with respect to the correlation time, the mean curvature and the tunnel’s geometry. Eventually, the mechanism of the symmetry breaking is elucidated.