Alternative escape for run-and-tumble particles from a potential with spatially random perturbations

Area of Science:

• Statistical Physics
• Soft Matter Physics
• Active Matter

Background:

• Self-propelled particles are influenced by environmental factors like disordered landscapes and thermal fluctuations.
• Run-and-tumble particles are a model system for self-propelled particles with constant speed and random direction changes.

Purpose of the Study:

• To investigate the escape properties of run-and-tumble particles from a random potential combining smooth and spatially random perturbation (SRP) components.
• To understand how SRPs affect escape probability, first passage time distributions, and particle dynamics.

Main Methods:

• Theoretical analysis of run-and-tumble particle dynamics in a composite potential.
• Investigation of escape probability and first passage time distributions under varying SRP intensity and correlation length.

Main Results:

• Spatially random perturbations (SRPs) generally enhance escape probability over higher potential barriers.
• SRPs reduce the peak of first passage time distributions, creating long tails, and show a linear dependence of mean first passage time on SRP intensity and correlation length.
• SRPs have a minor impact on the overall probability density function shape, causing only small-scale fluctuations.

Conclusions:

• The study elucidates the significant role of SRPs in modulating the escape dynamics of active particles.
• Findings support the potential for oriented transportation and sorting of active particles on disordered substrates.