Relaxation and Collective Excitations of Cluster Nano-Plasmas

TL;DR

This paper investigates the collective excitations in nano-plasmas generated in clusters after laser irradiation, using molecular dynamics simulations to analyze how these excitations emerge as cluster size increases.

Contribution

The study provides new data on the minimum stationary charge of clusters and characterizes the spatial structure and energy of eigenmodes in nano-plasmas.

Findings

Identification of the minimum stationary cluster charge.

Characterization of eigenmodes' spatial structure.

Observation of macroscopic collective excitations emerging with increasing cluster size.

Abstract

Nano-plasmas produced, e.g. in clusters after short-pulse laser irradiation, can show collective excitations as derived from the time evolution of fluctuations in thermodynamic equilibrium. Molecular dynamical simulations are performed for various cluster sizes. New data are obtained for the minimum value of the stationary cluster charge. The bi-local auto-correlation function gives the spatial structure of the eigenmodes, for which energy eigenvalues are obtained. Varying the cluster size, starting from a few-particles cluster, the emergence of macroscopic properties like collective excitations is shown.