OPTIMAL DIFFUSIVE TRANSPORT IN A TILTED PERIODIC POTENTIAL

2001 ◽  
Vol 01 (01) ◽  
pp. R25-R39 ◽  
Author(s):  
BENJAMIN LINDNER ◽  
MARCIN KOSTUR ◽  
LUTZ SCHIMANSKY-GEIER
Keyword(s):  
Diffusion Coefficient ◽  
Numerical Solution ◽  
Periodic Potential ◽  
Brownian Particle ◽  
Planck Equation ◽  
Diffusive Transport ◽  
Noise Strength ◽  
Diffusive Motion ◽  
Potential Mapping ◽  
Cumulative Process

We study the diffusive motion of an overdamped Brownian particle in a tilted periodic potential. Mapping the continuous dynamics onto a discrete cumulative process we find exact expressions for the diffusion coefficient and the Péclet number which characterize the transport. At a sufficiently strong but subcritical bias an optimized transport with respect to the noise strength is observed. These results are confirmed by numerical solution of the Fokker-Planck equation.

scholarly journals DIFFUSIVE TRANSPORT IN PERIODIC POTENTIALS: UNDERDAMPED DYNAMICS

2008 ◽  
Vol 08 (02) ◽  
pp. L155-L173 ◽  
Author(s):  
G. A. Pavliotis ◽  
A. Vogiannou
Keyword(s):  
Diffusion Coefficient ◽  
Periodic Potential ◽  
Diffusion Tensor ◽  
Brownian Particle ◽  
One Dimension ◽  
Diffusive Transport ◽  
Periodic Potentials ◽  
Arbitrary Dimensions ◽  
Higher Order Corrections ◽  
Rigorous Method

In this paper we present a systematic and rigorous method for calculating the diffusion tensor for a Brownian particle moving in a periodic potential which is valid in arbitrary dimensions and for all values of the dissipation. We use this method to obtain an explicit formula for the diffusion coefficient in one dimension which is valid in the underdamped limit, and we also obtain higher order corrections to the Lifson-Jackson formula for the diffusion coefficient in the overdamped limit. A numerical method for calculating the diffusion coefficient is also developed and is shown to perform extremely well for all values of the dissipation.

Enhanced Diffusion in a Model of Molecular Motors with Potential Switching

2019 ◽  
Vol 18 (02) ◽  
pp. 1940005 ◽  
Author(s):  
Ryota Shinagawa ◽  
Kazuo Sasaki
Keyword(s):  
Diffusion Coefficient ◽  
External Force ◽  
Molecular Motors ◽  
Periodic Potential ◽  
Brownian Particle ◽  
Molecular Motor ◽  
Free Diffusion ◽  
Enhanced Diffusion ◽  
Additional Peak ◽  
Diffusion Enhancement

Diffusion enhancement is a phenomenon in which the diffusion coefficient of a system is increased by an external force and it becomes larger than that of the force-free diffusion in thermal equilibrium. It is known that this phenomenon occurs for a Brownian particle in a periodic potential under a constant external force. Recently, it was found that diffusion enhancement also occurred in a biological molecular motor, whose moving part could move itself by switching the potentials generated by the other parts. It was shown that the diffusion coefficient exhibited peaks as a function of a constant external force. Here, we report the occurrence of an additional peak and investigate the condition governing its appearance.

Surface diffusion of a Brownian particle subjected to an external harmonic noise

2017 ◽  
Vol 31 (12) ◽  
pp. 1750082 ◽  
Author(s):  
Zhan-Wu Bai ◽  
Li-Ping Ding
Keyword(s):  
Diffusion Coefficient ◽  
Periodic Potential ◽  
Brownian Particle ◽  
Gaussian White Noise ◽  
Linear Functions ◽  
Potential Force ◽  
Negative Power ◽  
Absolute Value ◽  
Langevin Simulation ◽  
Harmonic Noise

Langevin simulation is performed to investigate the diffusion coefficient of a Brownian particle subjected to an external harmonic noise in a two-dimensional coupled periodic potential. Resonant diffusion phenomenon is observed as a result of the coupling between the central frequency of the spectral density of the harmonic noise and the frequency of the potential well bottom. The diffusion coefficient presents approximately linear functions of the strengths of the internal and external noises for low values of the strengths, these functions can be understood by the local linearization approximation of the potential force. The damping coefficient dependence of the diffusion coefficient in lower damping is well fitted by a negative power function, as an internal Gaussian white noise case does, but with a power whose absolute value is larger than 1.

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