title: Directing Brownian motion on a periodic surface.
abstract: We consider an overdamped Brownian particle, exposed to a two-dimensional, square lattice potential and a rectangular ac drive. Depending on the driving amplitude, the linear response to a weak dc force along a lattice symmetry axis consist in a mobility in basically any direction. In particular, motion exactly opposite to the applied dc force may arise. Upon changing the angle of the dc force relatively to the square lattice, the particle motion remains predominantly opposite to the dc force. The basic physical mechanism consists in a spontaneous symmetry breaking of the unbiased deterministic particle dynamics.
authors.affiliation: Universität Bielefeld, Fakultät für Physik, 33615 Bielefeld, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Speer
authors.forename: Ralf
authors.initials: R
authors.lastname: Eichhorn
authors.forename: Peter
authors.initials: P
authors.lastname: Reimann
mesh_terms: D004058:Diffusion; D007700:Kinetics; D016014:Linear Models; D008956:Models, Chemical; D013499:Surface Properties