title: Motion by stopping: rectifying Brownian motion of nonspherical particles.
abstract: We show that Brownian motion is spatially not symmetric for mesoscopic particles embedded in a fluid if the particle is not in thermal equilibrium and its shape is not spherical. In view of applications to molecular motors in biological cells, we sustain nonequilibrium by stopping a nonspherical particle at periodic sites along a filament. Molecular dynamics simulations in a Lennard-Jones fluid demonstrate that directed motion is possible without a ratchet potential or temperature gradients if the asymmetric nonequilibrium relaxation process is hindered by external stopping. Analytical calculations in the ideal gas limit show that motion even against a fluid drift is possible and that the direction of motion can be controlled by the shape of the particle, which is completely characterized by tensorial Minkowski functionals.
authors.affiliation: Institut für Theoretische Physik, Universität Erlangen-Nürnberg, Staudtstrasse 7, Erlangen, Germany.
authors.forename: Susan
authors.initials: S
authors.lastname: Sporer
authors.forename: Christian
authors.initials: C
authors.lastname: Goll
authors.forename: Klaus
authors.initials: K
authors.lastname: Mecke