Effect of anomalous diffusion on directed motion in a multiplicative noise driven flashing ratchet system
Department of Chemistry, Visva-Bharati University, Santiniketan, 731 235, India
Corresponding author: a email@example.com
Revised: 24 July 2009
Published online: 22 October 2009
In this paper we have studied the directed motion of a Brownian particle in a multiplicative noise driven flashing ratchet system. Our investigation shows the current (j) is either maximum or minimum in the super-diffusion (SPD) region depending on the asymmetric character of the ratchet potential. But the optimum behavior disappears for the symmetric ratchet potential and there is a current inversion around the normal diffusion (ND). With increase of half cycle period(tp/2) (which controls the on-off operation mechanism of the potential), j passes through a maximum and the peak height is the highest for the SPD. Also at low asymmetry in the system, the mobility is more dominating for the normal and the super-diffusion cases than the sub-diffusion. For large asymmetry in the ratchet potential, the diffusion control positive current is larger for the ND compared to the other cases. Finally, we observe that there is a maximum in the variation of current as a function of noise correlation time for SPD. But it disappears for the other cases.
PACS: 02.50.Ey – Stochastic processes / 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009