Energy landscape of relaxed amorphous silicon

TL;DR

This study investigates the energy landscape of relaxed amorphous silicon, revealing that relaxation mechanisms are local, uniformly distributed, and primarily limited by single-bond breaking, regardless of configuration details.

Contribution

It provides a comprehensive analysis of the energy landscape of amorphous silicon, highlighting the localized and configuration-insensitive nature of relaxation mechanisms.

Findings

Activated mechanisms are local in nature.

Activation energy is limited by breaking one bond.

The energy barrier distribution is insensitive to configuration details.

Abstract

We analyze the structure of the energy landscape of a well-relaxed 1000-atom model of amorphous silicon using the activation-relaxation technique (ART nouveau). Generating more than 40,000 events starting from a single minimum, we find that activated mechanisms are local in nature, that they are distributed uniformly throughout the model and that the activation energy is limited by the cost of breaking one bond, independently of the complexity of the mechanism. The overall shape of the activation-energy-barrier distribution is also insensitive to the exact details of the configuration, indicating that well-relaxed configurations see essentially the same environment. These results underscore the localized nature of relaxation in this material.