Non-affine deformations of inherent structure as signature of cooperativity in supercooled liquids

TL;DR

This paper identifies non-affinely rearranging regions in the inherent structures of supercooled liquids, revealing how static structural features correlate with cooperative dynamics and elastic heterogeneities in amorphous solids.

Contribution

It introduces the concept of non-affinely rearranging regions in inherent structures as static signatures of cooperativity in supercooled liquids.

Findings

Large rearrangements in IS are short-range correlated in liquids.

At low temperatures, smaller displacements are correlated over larger distances.

Non-affine domains in IS relate to cooperative regions in dynamics.

Abstract

We unveil the existence of non-affinely rearranging regions in the inherent structures (IS) of supercooled liquids by numerical simulations of two- and three-dimensional model glass formers subject to static shear deformations combined with local energy minimizations. In the liquid state IS, we find a broad distribution of rather large rearrangements which are correlated only over small distances. At low temperatures, the onset of the cooperative dynamics corresponds to much smaller displacements correlated over larger distances. This finding indicates the presence of non-affinely rearranging domains of relevant size in the IS deformation, which can be seen as the static counterpart of the cooperatively rearranging regions in the dynamics. This idea provides new insight into possible structural signatures of slow cooperative dynamics of supercooled liquids and supports the connections with elastic heterogeneities found in amorphous solids.