Long-time self-diffusion in disordered media

Abstract

Long-time self di usion coe cient is calculated over a broad range of densities from computer simulations of a two-dimensional system obeying Brownian dynamics and interacting through a Yukawa pairwise potential. The behavior of the di usion under changes of strength of the potential and density of particles is discussed and compared with bibliographical results. Furthermore, the e ects of an external driving force and the presence of xed particles are also considered. It is found that the di usion lowers with the density of particles, the strength of the potential and the presence of xed particles. On the contrary, an external force favors the di usion. Despite the e ect of the external force, a jammed state can be reached if density and proportion of xed particles are high enough.