Experimental identification of topological defects in 2D colloidal glass

TL;DR

This paper experimentally demonstrates the existence of topological defects in the vibrational modes of a 2D colloidal glass, linking them to soft spots and plastic flow, thus advancing understanding of disorder and dynamics.

Contribution

It provides the first experimental evidence of topological defects in the vibrational eigenspace of a disordered glass, connecting topology with structural softness and dynamics.

Findings

Topological defects are present in the vibrational modes of 2D colloidal glasses.

Defects correlate with soft spots prone to plastic deformation.

Topological defects influence the dynamics of disordered materials.

Abstract

Topological defects are singularities within a field that cannot be removed by continuous transformations. The definition of these irregularities requires an ordered reference configuration, calling into question whether they exist in disordered materials, such as glasses. However, recent work suggests that well-defined topological defects emerge in the dynamics of glasses, even if they are not evident in the static configuration. In this study, we reveal the presence of topological defects in the vibrational eigenspace of a two-dimensional experimental colloidal glass. These defects strongly correlate with the vibrational features and spatially correlate with each other and structural "soft spots", more prone to plastic flow. This work experimentally confirms the existence of topological defects in disordered systems revealing the complex interplay between topology, disorder, and dynamics.