Single-file dynamics with different diffusion constants

Summary, in English

We investigate the single-file dynamics of a tagged particle in a system consisting of N hardcore interacting particles (the particles cannot pass each other) which are diffusing in a one-dimensional system where the particles have different diffusion constants. For the two-particle case an exact result for the conditional probability density function (PDF) is obtained for arbitrary initial particle positions and all times. The two-particle PDF is used to obtain the tagged particle PDF. For the general N-particle case (N large) we perform stochastic simulations using our new computationally efficient stochastic simulation technique based on the Gillespie algorithm. We find that the mean square displacement for a tagged particle scales as the square root of time (as for identical particles) for long times, with a prefactor which depends on the diffusion constants for the particles; these results are in excellent agreement with very recent analytic predictions in the mathematics literature.

• Author: Tobias Ambjörnsson; Ludvig Lizana; Michael A. Lomholt; Robert J. Silbey
• Publishing year: 2008-11-14
• Language: English
• Publication/Series: The Journal of chemical physics
• Volume: 129
• Issue: 18
• Links: http://dx.doi.org/10.1063/1.3009853
• Document type: Journal article
• Publisher: American Institute of Physics (AIP)
• Topic: Other Physics Topics; Biophysics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0021-9606