Anomalous transport in the soft-sphere Lorentz model

TL;DR

This study investigates how the form of inter-particle interactions affects anomalous transport in crowded media, extending the Lorentz model with smooth potentials and confirming universal scaling behavior near criticality.

Contribution

The paper introduces a modified Lorentz model with smooth potentials to better represent realistic systems and demonstrates the universality of critical exponents in anomalous transport.

Findings

Anomalous transport at the critical point shares the same universal exponent as hard exclusion models.

Scaling behavior near the critical point confirms the universality of the exponent.

The Lorentz model with smooth potentials can describe long-range transport in real crowded environments.

Abstract

The sensitivity of anomalous transport in crowded media to the form of the inter-particle interactions is investigated through computer simulations. We extend the highly simplified Lorentz model towards realistic natural systems by modeling the interactions between the tracer and the obstacles with a smooth potential. We find that the anomalous transport at the critical point happens to be governed by the same universal exponent as for hard exclusion interactions, although the mechanism of how narrow channels are probed is rather different. The scaling behavior of simulations close to the critical point confirm this exponent. Our result indicates that the simple Lorentz model may be applicable to describing the fundamental properties of long-range transport in real crowded environments.