2025/06/04 by Leiming Chen, Chen, Leiming, Chiu Fan Lee +3
Engineering · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Characterization and Applications of Magnetic Nanoparticles #FOS: Physical sciences #Micro and Nano Robotics #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2506.03488
openalex publication_date 2025/06/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study two-dimensional chiral dry Malthusian flocks; that is, chiral polar-ordered active matter with neither number nor momentum conservation. In the absence of fluctuations, these form a ``time cholesteric", in which the velocity rotates uniformly in time at a fixed frequency. Fluctuations are described by the (2+1)-Kardar-Parisi-Zhang (KPZ) equation, which implies short-ranged orientational order. For weak chirality, the system is in the linear regime of the KPZ equation for a wide range of length scales, over which it exhibits quasi-long-ranged orientational order. Our predictions for velocity and density correlations are testable in both simulations and experiments.