Active Matter in Lateral Parabolic Confinement: From Subdiffusion to Superdiffusion

TL;DR

This study investigates how active particles confined laterally in a parabolic potential transition from subdiffusive to superdiffusive behavior, influenced by noise strength and confinement intensity, revealing diverse diffusion regimes.

Contribution

It provides a detailed analysis of the diffusive regimes of active particles under lateral parabolic confinement, highlighting the conditions leading to subdiffusion, normal diffusion, and superdiffusion.

Findings

Subdiffusion occurs due to restricted space from high confinement and noise.

Large confinement and noise lead to single-file diffusion-like behavior.

Low noise and confinement promote superdiffusive regimes with persistent motion.

Abstract

In this work we studied the diffusive behavior of active brownian particles under lateral parabolic confinement. The results showed that we go from subdiffusion to ballistic motion as we vary the angular noise strength and confinement intensity. We argued that the subdiffusion regimes appear as consequence of the restricted space available for diffusion (achieved either through large confinement and/or large noise); we saw that when there are large confinement and noise intensity, a similar configuration to single file diffusion appears; on the other hand, normal and superdiffusive regimes may occur due to low noise (longer persistent motion), either through exploring a wider region around the potential minimum in the transverse direction (low confinement), or by forming independent clusters (high confinement).