title: Observation of flux reversal in a symmetric optical thermal ratchet.
abstract: We demonstrate that a cycle of three holographic optical trapping patterns can implement a thermal ratchet for diffusing colloidal spheres and that the ratchet-driven transport displays flux reversal as a function of the cycle frequency and the intertrap separation. Unlike previously described ratchet models, the approach we describe involves three equivalent states, each of which is locally and globally spatially symmetric, with spatiotemporal symmetry being broken by the sequence of states.
authors.affiliation: Department of Physics and Center for Soft Matter Research, New York University, New York, NY 10003, USA.
authors.forename: Sang-Hyuk
authors.initials: SH
authors.lastname: Lee
authors.forename: Kosta
authors.initials: K
authors.lastname: Ladavac
authors.forename: Marco
authors.initials: M
authors.lastname: Polin
authors.forename: David G
authors.initials: DG
authors.lastname: Grier