Mean square displacement of a tracer particle in a hard-core lattice gas

Abstract

A simple theory is developed for hopping diffusion in hard-core lattice gases. Its predictions for the mean square displacement of a tracer particle as a function of time are found to be in good agreement with the results of Monte Carlo simulations on a quadratic lattice. For long times a logarithmic term is found in accord with mode-coupling predictions. Our predictions for the tracer diffusion coefficient agree with those of Tahir-Kheli.