Phase diagram and edge effects in the ASEP with bottlenecks

TL;DR

This paper explores how bottlenecks affect the phase diagram and current in the TASEP model, revealing that bottleneck position and size significantly influence transport properties, with implications for biological transport systems.

Contribution

The study introduces a novel analytical approach to analyze the impact of bottleneck position and size on TASEP phase diagrams and current, including the concept of effective boundary rates.

Findings

Bottleneck position near boundaries affects phase diagram and current.

Second, smaller bottleneck far from the first does not influence transport capacity.

Bottleneck length and position are crucial for transport efficiency.

Abstract

We investigate the totally asymmetric simple exclusion process (TASEP) in the presence of a bottleneck, i.e. a sequence of consecutive defect sites with reduced hopping rate. The influence of such a bottleneck on the phase diagram is studied by computer simulations and a novel analytical approach. We find a clear dependence of the current and the properties of the phase diagram not only on the length of the bottleneck, but also on its position. For bottlenecks near the boundaries, this motivates the concept of effective boundary rates. Furthermore the inclusion of a second, smaller bottleneck far from the first one has no influence on the transport capacity. These results will form the basis of an effective description of the disordered TASEP and are relevant for the modelling of protein synthesis or intracellular transport systems where the motion of molecular motors is hindered by immobile blocking molecules.