Single-file dynamics with different diffusion constants

Research output: Contribution to journalArticle


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.


External organisations
  • Massachusetts Institute of Technology
  • Niels Bohr Institute
  • University of Southern Denmark
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Physics Topics
Original languageEnglish
Article number185106
JournalThe Journal of chemical physics
Issue number18
Publication statusPublished - 2008 Nov 14
Publication categoryResearch
Externally publishedYes