title: 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 channel are studied using molecular dynamics 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 shapes (i.e., straight and circular). The transition from single-file diffusion to the two-dimensional diffusion regime is investigated. This transition [regarding the calculation of the scaling exponent (α) of the MSD (Δx(2)(t) ∝ t(α)] as a function of the width of the channel is shown to change depending on the channel's confinement profile. In particular, the transition can be either smooth (i.e., for a parabolic confinement potential) or rather sharp (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.
authors.affiliation: Departamento de Física, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil.
authors.forename: D
authors.initials: D
authors.lastname: Lucena
authors.forename: D V
authors.initials: DV
authors.lastname: Tkachenko
authors.forename: K
authors.initials: K
authors.lastname: Nelissen
authors.forename: V R
authors.initials: VR
authors.lastname: Misko
authors.forename: W P
authors.initials: WP
authors.lastname: Ferreira
authors.forename: G A
authors.initials: GA
authors.lastname: Farias
authors.forename: F M
authors.initials: FM
authors.lastname: Peeters
mesh_terms: D000465:Algorithms; D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D004058:Diffusion; D008956:Models, Chemical; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D003102:Colloids