Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2609.39439

Active spinners drive passive matter into chiral rotors

Dennis Schorn·Anpuj Nair S·Stijn van der Ham·Benno Liebchen·Hanumantha Rao Vutukuri
View original source ↗Read source document ↗Export metadata ↓

Abstract

Active spinners inject angular momentum into their surroundings without persistent translation, providing a route to chiral active matter distinct from self-propelled particles moving along curved trajectories. Recent studies have shown that spinner fluids can self-organize into rotating clusters with circulating edge currents characteristic of odd-viscous fluids. Whether angular-momentum injection alone can transmit chirality and edge-current dynamics to ordinary passive matter - and thus serve as a generic mechanism for imparting chiral functionality to undriven material components - remains an open question. Here, we show experimentally and numerically that purely rotational magnetic spinners can transfer chirality and edge-current dynamics to passive colloidal matter. At high passive-particle fraction, active spinners assemble into rotating clusters surrounded by passive matter. Remarkably, upon changing composition and spinner attraction, this organization turns inside out: passive colloids form rotating clusters surrounded by a chiral spinner fluid. These passive rotors exhibit edge currents and the same angular-velocity scaling, $|Ω|\sim R^{-2}$, as their active counterparts. A minimal model shows that spinner-mediated transverse and non-reciprocal interactions are sufficient to reproduce these complementary chiral states and their boundary-driven dynamics. Our results establish angular-momentum injection by active spinners as a route to endow otherwise passive matter with chirality, collective rotation and boundary transport.

Explore related subjects

cond-mat.soft

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Dennis Schorn, Anpuj Nair S, Stijn van der Ham, Benno Liebchen, Hanumantha Rao Vutukuri. 2026-09-30. Active spinners drive passive matter into chiral rotors. https://arxiv.org/abs/2609.39439

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Microphase Separation and Ionic Aggregation in Oppositely Charged End-Functionalized Polymer Blends

We study the phase behavior of binary blends of polymers with oppositely charged termini using an ion-correlation-augmented self-consistent field theory (IC-SCFT). Under the low dielectric conditions typical for organic polymer melts, strong ion correlations drive association of multiple chain ends, leading to emergent multichain architectures that go beyond a simple ion-paired diblock copolymer picture previously used to interpret recent experiments. At moderate to strong polymer segregation, the resulting phase diagram differs considerably from this effective-diblock prediction: ion clustering broadens the lamellar and cylindrical windows while suppressing the network phases, the reverse of the trend for end-charged diblock copolymers. At weak segregation, the two polymers remain miscible even as ion clustering persists, and decreasing chain length drives the clusters themselves through a sphere-to-cylinder-to-lamella shape transition, connecting continuously to the aggregation behavior of classical terminally charged ionomers in the limit when one of the polymer species shrinks to just the charged end. These results reveal that ion clustering -- beyond simple pairwise bonding -- shapes the self-assembly of end-charged polymer blends.

cond-mat.soft↗
arXiv2026

Calibrated shape-only recovery of membrane viscosities

Nearby relaxation rates make two membrane viscosities difficult to distinguish from a shape transient. We show how calibrated preparation removes this loss of local sensitivity in a linear Kelvin-Voigt sphere with finite area elasticity and intrinsic membrane dissipation. Two independent releases, with a known signed amplitude ratio and calibrated relative gain and timing, yield normal-displacement records whose fixed linear combination separates the shear and dilatational rates. Their common amplitude remains unknown. For fixed sampling, positive-definite weights, bounded positive rates and nonzero excitation, the amplitude-projected sensitivity has a positive lower bound even at rate coincidence. Without relative calibration, the paired sensitivity decreases linearly with the rate gap; the single tangential-release record decreases quadratically. The calibrated bound is compatible with fixed finite initial energy. A positive local bound also persists with independent ratio calibration of fixed positive precision under a Gaussian error model. Supplied elastic coefficients convert the recovered rates into the two surface viscosities. An unbounded spherical Stokes extension quantifies how bulk dissipation changes the modal patterns and provides a sufficient full-Jacobian criterion for retaining local material sensitivity.

cond-mat.soft↗
arXiv2026

Density and shape govern the dynamical self-organization of active matter on a closed surface

Morphogenesis emerges from dynamic feedback among geometry, mechanics, and chemistry; however, disentangling these contributions in living systems remains challenging. Here, we focus on the interplay between geometry and mechanics by developing a minimal in vitro model in which purified microtubules and kinesin motor clusters self-organize into a two-dimensional active nematic cortex at the surface of spherical water-in-oil droplets. The spherical geometry enforces a total topological charge of +2, here realized by four +1/2 defects whose trajectories reveal robust, self-sustained oscillations. Using full-surface reconstructions, we show that the collective dynamics of the defects lead to a periodic switching between planar and tetrahedral arrangements through alternating coiling and hemisphere-crossing phases. By tuning microtubule density, the system spans a continuum from a classic defect-dominated active nematic to a regime resembling an extensile filament confined to a curved surface, where low density is associated with increased trajectory variability and direction reversals. Geometric perturbations introduced through controlled squeezing redistribute curvature and induce the nucleation of additional defects, thereby reorganizing the entire topological landscape while preserving total charge. Together, these results show that periodic morphogenetic-like cycles, defect topology, and material organization can arise solely from the interplay of activity, density, and curvature. This reconstituted system provides a versatile platform for elucidating the coupling between mechanics and geometry underlying shape formation in active biological matter.

cond-mat.soft↗