Channel instability in binary mixtures with differential diffusivity.

Abstract

Rupture dynamics and pinch-off phenomena are fundamental for understanding instabilities in fluid dynamics and biological systems. In this study, we investigate the rupture of two-dimensional, channel-like configurations in a binary mixture of particles with differential diffusivities. Through computational simulations, we analyze the evolution of this instability under various conditions, identifying key parameters such as aspect ratio, particle density, and drift strength that influence the system's stability. While its behavior resembles the Plateau-Rayleigh instability (PRI), the underlying mechanism differs fundamentally, as PRI is restricted to three-dimensional systems. Interestingly, similar instabilities have been observed in chiral fluids, further supporting the existence of a novel instability mechanism unique to two-dimensional non-equilibrium systems. Our results suggest that this phenomenon is not a finite-size effect, but rather an intrinsic property of systems with differential diffusivities, offering new insights into pattern formation and instability dynamics in active matter.