Molecular dynamics simulation of nanofilament breakage in neuromorphic nanoparticle networks

TL;DR

This study uses molecular dynamics simulations to investigate the thermal breakage mechanisms of gold nanofilaments connecting nanoparticles, providing insights for neuromorphic nanoparticle network design.

Contribution

It introduces a detailed molecular dynamics model of nanofilament breakage, highlighting the effects of nanowire dimensions and structure on stability and melting behavior.

Findings

Atoms aggregate towards clusters, causing wire thinning and breakage.

Most of the system remains crystalline, with the middle region molten.

Terminal nanoparticles increase melting points and facilitate recrystallization.

Abstract

Neuromorphic computing systems may be the future of computing and cluster-based networks are a promising architecture for the realization of these systems. The creation and dissolution of synapses between the clusters are of great importance for their function. In this work, we model the thermal breakage of a gold nanofilament located between two gold nanoparticles via molecular dynamics simulations to study on the mechanisms of neuromorphic nanoparticle-based devices. We employ simulations of Au nanowires of different lengths ($2-8$ nm), widths ($0.4-0.8$ nm) and shapes connecting two Au$_{1415}$ nanoparticles (NPs) and monitor the evolution of the system via a detailed structural identification analysis. We found that atoms of the nanofilament gradually aggregate towards the clusters, causing the middle of the wire to gradually thin and then break. Most of the system remains crystalline during this process but the center is molten. The terminal NPs increase the melting point of the NWs by fixing the middle wire and act as recrystallization areas. We report a strong dependence on the width of the NWs, but also their length and structure. These results may serve as guidelines for the realization of cluster-based neuromorphic computing systems.