Effect of Nonlocal Interactions on the Hyperuniformity of Driven Dissipative Colloidal Systems

The experimental observation of hyperuniformity in driven dissipative colloidal systems [1] has sparked significant interest in understanding the underlying mechanisms. This study examines the role of nonlocal interactions between the particle configurations and their liquid medium by constructing a dynamic interplay within a two-phase medium: a spherical aggregate of hard spheres arranged in a close-packed Bravais lattice and the surrounding liquid phase. The interactions between these phases result in distinct hyperuniform states.

We begin by preparing the system for disaggregation, allowing the liquid phase to act on the aggregate until a solid-to-liquid transition occurs, at which point conventional pairwise and local interactions diminish in significance. Beyond this transition, particle motion is governed by unconstrained Brownian dynamics. Our findings reveal that the competition between the two phases leads to a variety of hyperuniform states, which we quantify using a novel geometric parameter. The hard-sphere interactions are modeled using an event-driven algorithm derived from the Langevin equation [2].

[1] Ü Seleme Nizam et al; Dynamic evolution of hyperuniformity in a driven dissipative colloidal system. 2021 J. Phys.: Condens. Matter 18 June 2021; 33: 304002.

[2] A. Scala et al; Event-driven Brownian dynamics for hard spheres. J. Chem. Phys. 7 April 2007; 126 (13): 134109.