Diffusion enhancement in a periodic potential under high-frequency space-dependent forcing

Bandyopadhyay, Malay ; Dattagupta, Sushanta ; Sanyal, Monamie (2006) Diffusion enhancement in a periodic potential under high-frequency space-dependent forcing Physical Review E, 73 (5). 051108_1-051108_7. ISSN 1063-651X

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Official URL: http://pre.aps.org/abstract/PRE/v73/i5/e051108

Related URL: http://dx.doi.org/10.1103/PhysRevE.73.051108

Abstract

We study the long-time behavior of an underdamped Brownian particle moving through a viscous medium and in a systematic potential, when it is subjected to a space-dependent high-frequency periodic force. When the frequency is very large, much larger than all other relevant system-frequencies, there is a Kapitsa time window wherein the effect of frequency-dependent forcing can be replaced by a static effective potential. Our analysis includes the case in which the forcing, in addition to being frequency-dependent, is space-dependent as well. The results of our analysis then lead to additional contributions to the effective potential. These are applied to the numerical calculation of the diffusion coefficient (D) for a Brownian particle moving in a periodic potential. Presented are numerical results, which are in excellent agreement with theoretical predictions and which indicate a significant enhancement of D due to the space-dependent forcing terms. In addition, we study the transport property (current) of an underdamped Brownian particle in a ratchet potential.

Item Type:Article
Source:Copyright of this article belongs to American Physical Society.
ID Code:9231
Deposited On:29 Oct 2010 11:13
Last Modified:16 May 2016 19:03

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