Emergence of Lanes and Turbulent-like Motion in Active Spinner Fluid

Abstract

Assemblies of self-rotating particles are gaining interest as a novel realization of active matter with unique collective behaviors such as edge currents and non-trivial dynamic states. Here, we develop a continuum model derived from coarse-grained equations of motions for a system of discrete spinners. We apply the model to explore the mixtures of spinners and same-spin phase separation. We find that the dynamics is strikingly sensitive to fluid inertia: In the inertialess system, after transient turbulent-like motion the spinners segregate and form steady traffic lanes. Contrary, at small but finite Reynolds number, the turbulent-like motion is sustained and the spinner population exhibit a chirality breaking transition: only population with a certain sense of rotation survives. The results shed light on the dynamic behavior of non-equilibrium materials exemplified by active spinners.

Simultaneous emergence of active turbulence and odd viscosity in a colloidal chiral active system

“…On the other hand, rotor systems have been shown to exhibit active turbulence without the emergence of a dominant length scale resulting in a power-law decay in the energy spectrum without intrinsic cutoff. 13,33 Interestingly, rotor systems have shown to either exhibit active turbulence, or to have an odd viscosity: 24,34 whether both features may occur simultaneously is still an open question, answered affirmatively in this paper.…”

Emergent phenomena in chiral active matter

“…The energy injected on the particle level is then transported to larger scales until it is taken out of the system dissipation scales, e.g., due to friction, and the dynamics Page 11 of 30 is reminiscent of 2D high Reynolds number turbulence. However, in chiral active systems the Reynolds number can be exceedingly small such that inertial contributions may be neglected and the phenomenon is called active turbulence [34,97,98].…”