Active chiral molecules in activity gradients

Abstract

While the behavior of active colloidal molecules is well studied by now for a constant activity, the effect of activity gradients is much less understood. Here we explore one of the simplest molecules in activity gradients, namely active chiral dimers composed of two particles with opposite active torques of the same magnitude. We show analytically that with increasing torque, the dimer switches its behavior from antichemotactic to chemotactic. The origin of the emergent chemotaxis is the cooperative exploration of activity gradient by the two particles. While one of the particles moves into higher activity regions, the other moves towards lower activity region resulting in a net bias in the direction of higher activity. We do a comparative study of chiral active particles with charged Brownian particles under magnetic field and show that despite the fundamental similarity in terms of their odd-diffusive behavior, their dynamics and chemotactic behavior are generally not equivalent. We demonstrate this explicitly in a dimer composed of oppositely charged active particles, which remains antichemotactic for any magnetic field.

References in corpus (24)

• Active Particles in Complex and Crowded Environments
• Self-motile colloidal particles: from directed propulsion to random walk
• Diffusive transport without detailed balance in motile bacteria: Does microbiology need statistical physics?
• Phototaxis of synthetic microswimmers in optical landscapes
• Effective Interactions in Active Brownian Suspensions
• Anomalous Diffusion of Symmetric and Asymmetric Active Colloids
• The physics of active polymers and filaments
• Light-induced self-assembly of active rectification devices
• How does a flexible chain of active particles swell?
• Optimal run-and-tumble based transportation of a Janus particle with active steering
• Adaptive, locally-linear models of complex dynamics
• Velocity distribution of a homogeneously driven two-dimensional granular gas
• Pulling and Pushing a Cargo With a Catalytically Active Carrier
• Escape rate of active particles in the effective equilibrium approach
• Active Colloidal Molecules
• Active Brownian filaments with hydrodynamic interactions: conformations and dynamics
• Brownian systems with spatially inhomogeneous activity
• Chemotaxis of cargo-carrying self-propelled particles
• Dynamics of active particles with space-dependent swim velocity
• Lorentz forces induce inhomogeneity and fluxes in active systems
• Correlations in multithermostat Brownian systems with Lorentz force
• Nondiffusive Fluxes in Brownian System with Lorentz Force
• Unusual stationary state in Brownian systems with Lorentz force
• Chemokinetic scattering, trapping, and avoidance of active Brownian particles