Eur. Phys. J. B 59, 63-68 (2007)
https://doi.org/10.1140/epjb/e2007-00255-7

Information and maximum power in a feedback controlled Brownian ratchet

¹ Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, Avenida Complutense s/n, 28040 Madrid, Spain
² LERMA, Observatoire de Paris and CNRS UMR 8112, 61 avenue de l'Observatoire, 75014 Paris, France

Corresponding authors: ^a feito@fis.ucm.es - ^b francao@fis.ucm.es

Received: 28 March 2007
Revised: 17 July 2007
Published online: 28 September 2007

Abstract

Closed-loop or feedback controlled ratchets are Brownian motors that operate using information about the state of the system. For these ratchets, we compute the power output and we investigate its relation with the information used in the feedback control. We get analytical expressions for one-particle and few-particle flashing ratchets, and we find that the maximum power output has an upper bound proportional to the information. In addition, we show that the increase of the power output that results from changing the optimal open-loop ratchet to a closed-loop ratchet also has an upper bound that is linear in the information.