Hyperuniformity with no fine tuning in sheared sedimenting suspensions

• Published in: Nature communications Vol. 9; no. 1; pp. 2836 - 7
• Main Authors: Wang, Jikai, Schwarz, J. M., Paulsen, Joseph D.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.07.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/923; 639/301/923/916; 639/301/923/966; 639/766/119; 639/766/530; Computer simulation; Homogenization; Humanities and Social Sciences; multidisciplinary; Scaling; Science; Science (multidisciplinary); Sedimentation; Sedimentation & deposition; Tuning; Variation
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-05195-4

Particle suspensions, present in many natural and industrial settings, typically contain aggregates or other microstructures that can complicate macroscopic flow behaviors and damage processing equipment. Recent work found that applying uniform periodic shear near a critical transition can reduce fluctuations in the particle concentration across all length scales, leading to a hyperuniform state. However, this strategy for homogenization requires fine tuning of the strain amplitude. Here we show that in a model of sedimenting particles under periodic shear, there is a well-defined regime at low sedimentation speed where hyperuniform scaling automatically occurs. Our simulations and theoretical arguments show that the homogenization extends up to a finite length scale that diverges as the sedimentation speed approaches zero. Suspensions appear in a wide range of industrial settings, and dispersing particles in a uniform manner throughout a fluid remains challenging for applications. Wang et al. obtain hyperuniform mixtures without fine tuning by harnessing self-organized criticality due to slow sedimentation and shear.