Anti-hyperuniform Critical States of Active Topological Defects
arXiv:2509.22911 · doi:10.1088/1361-6633/ae075e
Abstract
Topological defects are fundamental to the collective dynamics of non-equilibrium systems and in active matter, mediating spontaneous flows, dynamic self-organization, and emergent pattern formation. Here, we reveal critical states in active nematics, marked by slowed defect density relaxation, amplified fluctuations, and heightened sensitivity to activity. Near criticality, defect interactions become long-ranged, scaling with system size, and the system enters an anti-hyperuniform regime with giant number fluctuations of topological defects and defect clustering. This transition reflects a dual scaling behavior: fluctuations are uniform at small scales but become anti-hyperuniform at larger scales, \tm{as supported by experimental measurements on large-field-of-view endothelial monolayers. We find that these anti-hyperuniform states with multiscale defect density fluctuations are robust to varying parameters, introducing frictional damping, and changing boundary conditions.} Finally, we show that the observed anti-hyperuniformity originates from defect clustering, distinguishing this transition from defect-unbinding or phase separation processes. Beyond fundamental implications for non-equilibrium systems, these results may inform biological contexts where topological defects are integral to processes such as morphogenesis and collective cellular self-organization.
This is the Accepted Manuscript version of an article accepted for publication in Reports on Progress in Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it
References in corpus (39)
- Novel type of phase transition in a system of self-driven particles
- Collective motion
- The Mechanics and Statistics of Active Matter
- Flocks, herds, and schools: A quantitative theory of flocking
- Athermal Phase Separation of Self-Propelled Particles with no Alignment
- Hydrodynamic fluctuations and instabilities in ordered suspensions of self-propelled particles
- Local Density Fluctuations, Hyperuniformity, and Order Metrics
- Hyperuniform States of Matter
- The 2019 Motile Active Matter Roadmap
- Topological defect launches 3D mound in the active nematic sheet of neural progenitors
- Diffusive transport without detailed balance in motile bacteria: Does microbiology need statistical physics?
- Hierarchical structures of amorphous solids characterized by persistent homology
- Defect annihilation and proliferation in active nematics
- Orientational order of motile defects in active nematics
- Universal scaling behavior of non-equilibrium phase transitions
- Steady-state hydrodynamic instabilities of active liquid crystals: Hybrid lattice Boltzmann simulations
- Velocity Correlations in an Active Nematic
- Topological defects promote layer formation in Myxococcus xanthus colonies
- Pore-geometry recognition: on the importance of quantifying similarity in nanoporous materials
- Defect-mediated morphologies in growing cell colonies
- Tunable structure and dynamics of active liquid crystals
- Shearing active gels close to the isotropic-nematic transition
- Instabilities and Topological Defects in Active Nematics
- Vorticity, Defects and Correlations in Active Turbulence
- Defect unbinding in active nematics
- Large-scale chaos and fluctuations in active nematics
- Theory of defect-mediated morphogenesis
- Emergence of active nematics in bacterial biofilms
- Correlation lengths in hydrodynamic models of active nematics
- Active turbulence in active nematics
- Dynamics of defects in active nematics
- Active nematic materials with substrate friction
- Hydrodynamics of Active Defects: from order to chaos to defect ordering
- The low noise phase of a 2d active nematic
- A mesoscopic field theoretical approach for active systems
- Local Number Fluctuations in Hyperuniform and Nonhyperuniform Systems: Higher-Order Moments and Distribution Functions
- Binding self-propelled topological defects in active turbulence
- Giant number fluctuations in dry active polar fluids: A shocking analogy with lightning rods
- Nonlinear spontaneous flow instability in active nematics