On the geometry of topological defects in glasses

TL;DR

This study explores the geometry of topological defects in 3D glasses, revealing their scale-invariant structures and their influence on plastic deformation and energy dissipation, thus linking eigenmode topology to material behavior.

Contribution

It uncovers the geometric nature of topological defects in glasses and their role in plasticity, extending concepts from crystalline to disordered materials.

Findings

Defects form scale-invariant, quasi-linear structures at low frequencies.

Eigenmode topology shapes plastic deformation in 3D glasses.

Topological defects are linked to energy dissipation and relaxation dynamics.

Abstract

Recent studies point out far-reaching connections between the topological characteristics of structural glasses and their material properties, paralleling results in quantum physics that highlight the relevance of the nature of the wavefunction. However, the structural arrangement of the topological defects in glasses has so far remained elusive. Here we investigate numerically the geometry and statistical properties of the topological defects related to the vibrational eigenmodes of a prototypical three-dimensional glass. We find that at low-frequencies these defects form scale-invariant, quasi-linear structures and dictate the plastic events morphology when the system is subjected to a quasi-static shear, i.e., the eigenmode geometry shapes plastic behavior in 3D glasses. Our results indicate the existence of a deep link between the topology of eigenmodes and plastic energy dissipation in disordered materials, thus generalizing the known connection identified in crystalline materials. This link is expected to have consequences also for the relaxation dynamics in the liquid state, thus opening the door for a novel approach to describe this dynamics.