Nesta quarta-feira, dia 31 de Agosto de 2011, às 13:15hs, na Sala 03, Diego Lucena apresentará o trabalho intitulado

Transition from single-file to two-dimensional diffusion of interacting particles in a quasi-one-dimensional channel

ABSTRACT: Diffusive properties of a monodisperse system of interacting particles confined to a quasi-one-dimensional (Q1D) channel are studied using molecular dynamics (MD) simulations. We calculate numerically the mean-squared displacement (MSD) and investigate the influence of the width of the channel (or the strength of the confinement potential) on diffusion in finite-size channels of different shape (i.e., straight and circular). The transition from single-file diffusion (SFD) to the two-dimensional diffusion regime is investigated. This transition, as a function of the width of the channel, is shown to change dramatically depending on the channel’s confinement profile, in particular it can be either smooth (i.e., for a parabolic confinement potential) or rather sharp/stepwise (i.e., for a hard-wall potential), as distinct from infinite channels where this transition is abrupt. This result can be explained by qualitatively different distributions of the particle density for the different confinement potentials.