Origin of Spatiotemporal Fluctuations in Discontinuous Shear Thickening

TL;DR

This paper investigates the origins of large spatiotemporal fluctuations in discontinuous shear thickening (DST) using stochastic thermodynamics, revealing a non-equilibrium dichotomy and collective behaviors that underpin these complex transitions.

Contribution

It introduces a novel application of stochastic thermodynamics to uncover the mechanisms behind fluctuations in DST, highlighting a simple dichotomy in non-equilibrium phase transitions.

Findings

Identified a non-equilibrium dichotomy in fluctuation mechanisms.

Revealed collective behaviors across the shear thickening transition.

Demonstrated the role of stochastic thermodynamics in understanding non-equilibrium phase transitions.

Abstract

Rheological phase transitions open the door to the less explored realm of non-equilibrium phase transitions. The main mechanism driving these transitions is usually mechanical perturbation by shear--- an unjamming mechanism. Investigating discontinuous shear thickening (DST) is challenging because the shear counterintuitively acts as a jamming mechanism. Moreover, at the brink of this transition, a thickening material exhibits fluctuations that extend both spatially and temporally. Despite recent extensive research, the origins of such spatiotemporal fluctuations remain unidentified. Here, we investigate large fluctuations in DST by using versatile tools of stochastic thermodynamics. We discover a non-equilibrium dichotomy in the underlying mechanisms that give rise to large fluctuations and demonstrate that this dichotomy is a manifestation of novel collective behaviors across the transition. We then reveal the origin of spatiotemporal fluctuations in the shear thickening transition. Our study emphasizes the roles of stochastic thermodynamics tools in investigating non-equilibrium phase transitions, and demonstrates that these transitions are accompanied by simple dichotomies. We expect that our general approach will pave the way to unmasking the nature of non-equilibrium phase transitions.