Microscopic Description of Yielding in Glass Based on Persistent Homology

TL;DR

This paper uses persistent homology to analyze structural changes in glasses under shear, revealing that robust holes diminish after yielding and the structure resembles quickly quenched glass, highlighting geometric factors in yielding.

Contribution

It introduces a novel application of persistent homology to understand microscopic structural changes during yielding in glasses.

Findings

Robust holes decrease after yielding

Post-yield structures resemble quickly quenched glass

Persistent homology reveals geometric role in yielding

Abstract

Persistent homology (PH) was applied to probe the structural changes of glasses under shear. PH associates each local atomistic structure in an atomistic configuration to a geometric object, namely, a hole, and evaluates the robustness of these holes against noise. We found that the microscopic structures were qualitatively different before and after yielding. The structures before yielding contained robust holes, the number of which decreased after yielding. We also observed that the structures after yielding approached those of quickly quenched glass. This work demonstrates the crucial role of robust holes in yielding and provides an interpretation based on geometry.