Optimal noise for vortex of self-propelled particles around an obstacle.

We investigate the influence of thermal noise on the formation and dynamics of vortex of self-propelled particles (SPPs) around a circular obstacle using numerical simulations. In the absence of symmetry-breaking factors, spherical SPPs can spontaneously form a sustained vortex near the obstacle when particle activity is sufficiently high and the obstacle size lies within a suitable range. We show that noise not only induces transition between the vortex state and the random state but also plays a non-monotonic role in the behaviors of the vortex. In particular, there exists an optimal noise level that maximizes both the vortex speed and polarity alignment of the first particle layer, as well as the rate of their linear decay with distance from the obstacle. The underlying mechanism arises from the noise-dependent particle exchange process and the biased selection of incoming particles according to their polarities. In addition, the angular fluctuation of cluster thickness and the interlayer friction of particles also exhibit non-monotonic variations with noise. Pressure analysis demonstrates that the swimming pressure dominates and decreases near the obstacle due to tangential particle orientation, analogous to the reduced pressure in flowing fluids compared to stationary ones. Remarkably, the radial pressure shows a non-monotonic dependence on noise as well, reflecting the complex role of thermal noise in mediating the coupling between particle velocity and orientation. Our results highlight the constructive role of thermal noise in promoting collective vortex motion, thereby enriching the understanding of noise-induced effects in active matter systems.

• Publication year

  2026

• Venue

  Journal of Chemical Physics

• Publication date

  2026-01-02

• Fields of study

  Medicine, Physics

• Identifiers
  DOI 10.1063/5.0304820PMID 41480911
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• No claims are published for this paper.

• No concepts are published for this paper.

• Fluctuation induced network patterns in active matter with spatially correlated noise.

  2025cited by this paper
• Role of Noise-Modulated Self-Propulsion in Driving Spatiotemporal Orders in Active Systems.

  2025cited by this paper
• Collective motion of self-trapping chiral active particles induced by a noisy geometric environment.

  2025cited by this paper
• Deformation-induced phase separation of active vesicles.

  2024cited by this paper
• Dynamical clustering and wetting phenomena in inertial active matter

  2024cited by this paper
• Collective dynamics of active dumbbells near a circular obstacle.

  2024cited by this paper
• Spontaneous unidirectional rotation of a symmetric gear driven by spherical active particles

  2024cited by this paper
• Noise-induced collective actuation in active solids.

  2023cited by this paper
• Nonvanishing optimal noise in cellular automaton model of self-propelled particles

  2022cited by this paper
• Obstacle-induced giant jammed aggregation of active semiflexible filaments.

  2022cited by this paper
• Noise-induced swarming of active particles.

  2022cited by this paper
• Dynamical clustering interrupts motility-induced phase separation in chiral active Brownian particles.

  2021cited by this paper
• Rotation reversal of a ratchet gear powered by active particles.

  2021cited by this paper
• Absorption of self-propelled particles into a dense porous medium.

  2021cited by this paper
• Ising-like Critical Behavior of Vortex Lattices in an Active Fluid.

  2021cited by this paper
• Dynamic Assembly of Active Colloids: Theory and Simulation

  2020cited by this paper
• Vortex formation of spherical self-propelled particles around a circular obstacle.

  2020cited by this paper
• Transport of self-propelled particles across a porous medium: trapping, clogging, and the Matthew effect.

  2020cited by this paper
• Wetting of a solid surface by active matter.

  2020cited by this paper
• Local stress and pressure in an inhomogeneous system of spherical active Brownian particles

  2019cited by this paper
• Hydrodynamics of random-organizing hyperuniform fluids

  2019cited by this paper
• Assembly structures and dynamics of active colloidal cells.

  2019cited by this paper
• Flow and clogging of particles in shaking random obstacles.

  2019cited by this paper
• Microfluidic Pump Driven by Anisotropic Phoresis

  2018cited by this paper
• Clogging and depinning of ballistic active matter systems in disordered media.

  2018cited by this paper
• Self-Propelled Nanomotors for Thermomechanically Percolating Cell Membranes.

  2018cited by this paper
• Curvature-dependent tension and tangential flows at the interface of motility-induced phases.

  2018cited by this paper
• A swarm of slippery micropropellers penetrates the vitreous body of the eye

  2018cited by this paper
• Microrotor of a chain-grafted colloidal disk immersed in the active bath: The impact of particle concentration, grafting density, and chain rigidity.

  2018cited by this paper
• Nonequilibrium strongly hyperuniform fluids of circle active particles with large local density fluctuations

  2018cited by this paper
• Mechanical pressure and momentum conservation in dry active matter

  2017cited by this paper
• Spontaneous symmetry breaking induced unidirectional rotation of a chain-grafted colloidal particle in the active bath.

  2017cited by this paper
• Collective rotations of active particles interacting with obstacles

  2017cited by this paper
• Wetting Transitions Displayed by Persistent Active Particles.

  2017cited by this paper
• Active Particles in Complex and Crowded Environments

  2016cited by this paper
• Dewetting and spreading transitions for active matter on random pinning substrates.

  2016cited by this paper
• Ultrasound-Propelled Nanocups for Drug Delivery

  2015cited by this paper
• Swimming in a crystal.

  2014cited by this paper
• Nonequilibrium equation of state in suspensions of active colloids

  2014cited by this paper
• Pressure is not a state function for generic active fluids

  2014cited by this paper
• Self-propelled particle transport in regular arrays of rigid asymmetric obstacles.

  2014cited by this paper
• Motility-Induced Phase Separation

  2014cited by this paper
• Swim pressure: stress generation in active matter.

  2014cited by this paper
• Pressure and phase equilibria in interacting active brownian spheres.

  2014cited by this paper
• Active matter transport and jamming on disordered landscapes.

  2014cited by this paper
• Diffusion, subdiffusion, and trapping of active particles in heterogeneous media.

  2013cited by this paper
• Optimal noise maximizes collective motion in heterogeneous media.

  2013cited by this paper
• Hydrodynamics of soft active matter

  2013cited by this paper
• Rapid delivery of drug carriers propelled and navigated by catalytic nanoshuttles.

  2010cited by this paper
• Noise-induced transition from translational to rotational motion of swarms.

  2004cited by this paper
• Novel type of phase transition in a system of self-driven particles.

  1995cited by this paper

• No citing papers are available for this paper.