Diffusion of a bidisperse system of particles in a quasi-one-dimensional channel: The crossover between one-and-two-dimensional diffusion

P. M. CENTRES,; S. BUSTINGORRY

Conferencia; StatPhys2019; 2019

The single-file diffusion problem receives attention for both its diverse applications and its importance as the simplest non-trivial particle interacting problem. To better understand the crossover between one- and two-dimensional diffusion with volume exclusion, we here study the diffusion of bidisperse systems of particles using numerical simulations. The particles are confined to move in a long quasi-one-dimensional channel and with entropic repulsion among them. The movement of particles has been characterized by the global roughness of the particles instead of the mean square displacement. If both particles have a diameter slightly smaller than the width of the channel, they show a single-file diffusion process, due to their sequential ordering. On the contrary, if the size of the particles is such that only small particles can move around other particles, thus breaking the strict label order of the one-dimensional problem, a crossover to different diffusion regimes is observed. This crossover has been studied as a function of the width of the channel and the diameters of the particles.