title: Realization of a feedback controlled flashing ratchet.
abstract: A flashing ratchet transports diffusive particles using a time-dependent, asymmetric potential. The particle speed is predicted to increase when a feedback algorithm based on the particle position is used. We have experimentally realized such a feedback ratchet using an optical line trap, and observed that use of feedback increases velocity by up to an order of magnitude. We compare two different feedback algorithms for small particle numbers, and find good agreement with simulations. We also find that existing algorithms can be improved to be more tolerant to feedback delay times.
authors.affiliation: Department of Physics and Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1274, USA. blopez1@uoregon.edu
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Lopez
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Kuwada
authors.forename: Erin M
authors.initials: EM
authors.lastname: Craig
authors.forename: Brian R
authors.initials: BR
authors.lastname: Long
authors.forename: Heiner
authors.initials: H
authors.lastname: Linke
mesh_terms: D000465:Algorithms; D004058:Diffusion; D005246:Feedback; D008962:Models, Theoretical; D049329:Nanostructures / Q000737:chemistry*