Shear induced solidification of athermal systems with weak attraction

TL;DR

This study demonstrates that weakly attractive, frictionless particles can be driven into solid-like states through shear, revealing a shear stress-dependent transition with implications for the jamming phase diagram.

Contribution

It introduces the concept of shear-induced solidification in weakly attractive athermal systems and characterizes the transition from gel-like to jammed states.

Findings

Shear-driven solids can be formed at various packing fractions.

A critical shear stress $\sigma_c$ marks the transition to marginally jammed states.

Properties of shear-driven solids depend strongly on shear stress, not just packing fraction.

Abstract

We find that unjammed packings of frictionless particles with rather weak attraction can always be driven into solid-like states by shear. The structure of shear-driven solids evolves continuously with packing fraction from gel-like to jamming-like, but is almost independent of the shear stress. In contrast, both the density of vibrational states (DOVS) and force network evolve progressively with the shear stress. There exists a packing fraction independent shear stress $\sigma_c$, at which the shear-driven solids are isostatic and have a flattened DOVS. Solid-like states induced by a shear stress greater than $\sigma_c$ possess properties of marginally jammed solids and are thus strictly-defined shear jammed states. Below $\sigma_c$, states at all packing fractions are under isostaticity and share common features in the DOVS and force network, although their structures can be rather different. Our study reveals the significance of the shear stress in determining properties of shear-driven solids and leads to an enriched jamming phase diagram for weakly attractive particles.