Resolving Structural Avalanches in Amorphous Carbon with Arclength Continuation

TL;DR

This paper introduces a novel arclength continuation method to analyze and decompose avalanches in amorphous carbon, revealing their latent structure and improving the understanding of their energetics and dynamics.

Contribution

It develops a systematic energy landscape approach using arclength continuation to resolve avalanche structures and dynamics in amorphous solids, a novel application in this context.

Findings

Avalanches have well-separated local minima prior to onset.

Arclength continuation provides an event-driven framework for avalanche analysis.

The method eliminates time-step effects in statistical avalanche properties.

Abstract

Plastic deformation in amorphous solids is carried by localized shear transformations that self-organize into avalanches. In amorphous carbon modeled with a machine-learned interatomic potential, we find that the energetics and organization of these avalanches can be resolved by systematically following the underlying energy landscape. With a pseudo-arclength numerical continuation framework, we decompose avalanches into constituent shear transformations and determine their strain-dependent energetics. Our analysis shows that, prior to onset, avalanches have a latent structure that consists of well-separated local minima. We further demonstrate that arclength continuation yields an event driven framework for following avalanche dynamics, eliminating time-step effects on statistical avalanche properties such as distributions of stress drops.