Volume 85, Number 2, January 2009
Article Number 26002
Number of page(s) 6
Section Condensed Matter: Structural, Mechanical and Thermal Properties
Published online 29 January 2009
EPL, 85 (2009) 26002
DOI: 10.1209/0295-5075/85/26002

The origin of intermittent dynamics in the $\mth{\rho\to 1}$ lattice gas model

F. M. Terraneo, P. Pinto and K. A. Dawson

School of Chemistry and Chemical Biology, University College Dublin - Belfield, Dublin 4, Ireland, EU

received 9 July 2008; accepted in final form 19 December 2008; published January 2009
published online 29 January 2009

The dilute lattice gas model is presented here as a paradigmatic illustration of the connection between subdiffusive behaviour, intermittency and the motion of available (empty) space. Applying a framework based on Continuous Time Random Walk theory, we are able to show how subdiffusive motion arises and how, and when, it crosses over to a diffusive regime. The relevant timescales, $\tau _{c}$ and $\tau ^{\star}$, using arguments coming from simple principles are related to the (average) distance between vacant positions, $\xi $. Quantities of interest, such as the mean square displacement and the number of movements, are predicted and compared to simulation results.

PACS - Mass diffusion, including self-diffusion, mutual diffusion, tracer diffusion, etc.
05.40.Fb - Random walks and Levy flights.
64.70.P- - Glass transitions of specific systems.

© EPLA 2009