Malleability at the extreme nanoscale: Slow and fast quakes of few-body systems

TL;DR

This study investigates the complex deformation behaviors of ultra-small metal nanoparticles, revealing controllable slow and fast atomic quakes with potential for experimental detection and applications.

Contribution

It uncovers the bifurcation mechanism between slow and fast quakes in nanoparticles and demonstrates control over quake type via strain amplitude.

Findings

Fast quakes release energy abruptly.

Slow quakes build energy gradually and are silent.

Electrical conductance can distinguish quake types.

Abstract

We explore the malleability of ultra-small metal nanoparticles by means of ab initio calculations. It is revealed that, when strained, such nanoparticles exhibit complex behavior, including bifurcation between slow and fast quakes of their atomic structure, despite being few-body systems. We show the bifurcation to arise from the collapse of the nanoparticle's stiffness and a broken soft mode symmetry, and that whether a slow or fast quake occurs can be controlled by varying the amplitude of the externally applied strains. We predict that while energy is released abruptly in a fast quake, surprisingly, it continues to build up during a slow quake and that, in common with slow-slip geological earthquakes, the slow nanoparticle quake is a silent precursor to a fast "seismic" quake. We show that electrical conductance and force measurements can detect and distinguish between slow and fast quakes, opening the way for experiments and potential applications of these phenomena.