Optimal diffusion of chiral active particles with strategic reorientations

Area of Science:

• Physics
• Statistical Mechanics
• Soft Matter

Background:

• Active Brownian particles exhibit complex dynamics influenced by self-propulsion and rotational motion.
• Chirality in active particles leads to circular trajectories, often resulting in slow long-time transport.
• Tumbling events interrupt trajectories, significantly altering particle dynamics and transport properties.

Purpose of the Study:

• To investigate the interplay between chirality and tumbling in active Brownian particle dynamics.
• To determine if controlled tumbling can overcome the slow transport induced by chiral motion.
• To quantify the enhancement of diffusion through optimized tumbling strategies.

Main Methods:

• Derivation of exact expressions for the orientational propagator and correlations.
• Calculation of the first two moments of particle displacement.
• Analysis of effective diffusion coefficients under various tumbling strategies.

Main Results:

• Interrupting chiral circular motion with appropriately timed tumbles enhances particle diffusion.
• Optimized tumbling rates lead to enhanced diffusion, with symmetric tumbles resulting in a universal effective diffusion coefficient.
• Asymmetric tumbles can further enhance diffusion beyond symmetric strategies, with specific cases like directional reversal and fixed-angle tumbles analyzed.

Conclusions:

• Strategic tumbling is a viable mechanism to enhance the transport of chiral active particles.
• The study provides a theoretical framework for understanding and controlling active matter diffusion.
• Optimal tumbling strategies offer a pathway to engineer faster-moving active particles for various applications.