Single-file diffusion of interacting particles in a one-dimensional channel

Abstract

Molecular diffusion in unidimensional channel structures (single-file diffusion) is important to understand the behavior of, e.g., colloidal particles in porous materials (zeolites) and superconducting vortices in 1-dimensional (1D) channels. Here the diffusion of charged massive particles in a 1D channel is investigated using the Langevin Dynamics (LD) simulations. We analyze different regimes based on the hierarchy of the interactions and damping mechanisms in the system and we show that, contrary to previous findings, single-file diffusion depends on the inter-particle interaction and could be suppressed if the interaction is strong enough displaying a subdiffusive behavior slower than t 1/2 , in agreement with recent experimental observations in colloids and charged metallic balls.

Single-file diffusion of particles with long-range interactions: Damping and finite-size effects

“…The fact that this time scales as N 2 explains why this long time regime is seldom seen in simulations (to our knowledge, the only exception is [32]) or experiments. This is clearly illustrated by our Fig.…”

“…In [32], they simulate the full Langevin equation but they do not display data for a sufficiently small time to observe the t 2 scaling. …”

Diffusion of interacting particles in discrete geometries: Equilibrium and dynamical properties

“…In an infinitely long onedimensional equilibrium system single-file diffusion occurs [50,51], resulting in x(t) ∝ √ t and D s = 0. In higher-dimensional systems the diffusion is normal.…”

Tunable diffusion of magnetic particles in a quasi-one-dimensional channel

“…Diffusion is strongly modified in confined systems, and may lead to single-file diffusion (SFD) [34][35][36][37][38][39][40][41][42], which is directly related to the geometrical constrains imposed by an external confining potential. Furthermore, q1D systems can be used as models for the study of collective phenomena in low dimensional systems, e.g, vortex matter in type-II superconductors [43,44], colloidal particles [45,46] and dusty plasmas.…”