2024/03/20 by Cody D. Schimming, Schimming, Cody D., C. J. O. Reichhardt +3
Computer Science · Physics and Astronomy · #Chaos control and synchronization #FOS: Physical sciences #Nonlinear Dynamics and Pattern Formation #Soft Condensed Matter (cond-mat.soft) #stochastic dynamics and bifurcation
paper · pdf · doi:10.48550/arxiv.2403.13733
openalex publication_date 2024/03/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We numerically investigate the effect of a periodic array of asymmetric obstacles in a two-dimensional active nematic. We find that activity in conjunction with the asymmetry leads to a ratchet effect or unidirectional flow of the fluid along the asymmetry direction. The directional flow is still present even in the active turbulent phase when the gap between obstacles is sufficiently small. We demonstrate that the dynamics of the topological defects transition from flow-mirroring to smectic-like as the gap between obstacles is made smaller, and explain this transition in terms of the pinning of negative winding number defects between obstacles. This also leads to a non-monotonic ratchet effect magnitude as a function of obstacle size, so that there is an optimal obstacle size for ratcheting at fixed activity.