Molecular traffic control in single-file networks with fast catalysts

TL;DR

This paper models molecular traffic control in single-file networks with fast catalysts, analyzing particle diffusion, stationary density profiles, and currents, revealing non-analytic behavior at large transition rates through theoretical and simulation methods.

Contribution

It introduces a model for molecular traffic control in crossed single-file systems, analyzing stationary states and currents with a focus on non-analytic behavior at high transition rates.

Findings

Stationary currents depend non-linearly on reservoir densities.

Non-analytic behavior emerges at large transition rates.

Monte Carlo simulations confirm theoretical results.

Abstract

As a model for molecular traffic control (MTC) we investigate the diffusion of hard core particles in crossed single-file systems. We consider a square lattice of single-files being connected to external reservoirs. The (vertical) alpha-channels, carrying only A-particles, are connected to reservoirs with constant density ra. B-particles move along the (horizontal) beta-channels, which are connected to reservoirs of density rB. We allow the irreversible transition A to B at intersections. We are interested in the stationary density profile in the alpha- and beta- channels, which is the distribution of the occupation probabilities over the lattice. We calculate the stationary currents of the system and show that for sufficiently long channels the currents (as a function of the reservoir densities) show in the limit of large transition rates non analytic behavior. The results obtained by direct solution of the master equation are verified by kinetic Monte Carlo simulations.