Eur. Phys. J. B (2012) 85: 287
https://doi.org/10.1140/epjb/e2012-30298-4

Regular Article

Effect of harmonic noise on a Brownian particle in a ratchet periodic potential

Faculty of Science, Kunming University of Science and Technology, Kunming 650500, P.R. China

^a e-mail: lrnie@163.com

Received: 6 April 2012
Received in final form: 7 June 2012
Published online: 20 August 2012

Abstract

A Brownian particle in a ratchet periodic potential driven by harmonic noise, which is produced through a RLC oscillation circuit with Gaussian white noise, is investigated. The mean velocity and stationary probability distribution function (SPDF) of the system are obtained by means of numerical simulations. We also used the power spectrum of the harmonic noise, the peak position and semi-height width of which can be changed by modulating the driving oscillation circuit’s parameters, to analyse contributions of characteristics of the power spectrum to the mean velocity. The results indicate that: (i) appropriate peak position and semi-height width of the harmonic noise’s power spectrum can maximise the particle’s mean velocity; (ii) the SPDF undergoes a state transition from monostability  →  bistability  →  tristability  →  monostability as the Gaussian white noise intensity is increased, and the other parameters of the driving oscillation circuit can also modify the system’s state.