Abstract
The Brownian motion of a particle in a one-dimensional periodic potential subjected to a uniform external force F is studied. Using the formula for the diffusion coefficient D obtained by other authors and an alternative one derived from the Smoluchowski equation in the present work, D is compared with the differential mobility μ = dυ/dF where υ is the average velocity of the particle. Analytical and numerical calculations indicate that inequality D ≥ μkBT, with kB the Boltzmann constant and T the temperature, holds if the periodic potential is symmetric, while it is violated for asymmetric potentials when F is small but nonzero.
Original language | English |
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Pages (from-to) | 2226-2232 |
Number of pages | 7 |
Journal | journal of the physical society of japan |
Volume | 74 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2005 Aug |
Externally published | Yes |
Keywords
- Brownian motion
- Diffusion coefficient
- Mobility
- Smoluchowski equation
ASJC Scopus subject areas
- Physics and Astronomy(all)