Electronic oscillations in ionized sodium nanoclusters

Irradiation of nanosized metallic clusters by femtosecond laser pulses of moderate intensities (1012−1014 W cm−2) leads to creation of the so-called electron–ion nanoplasma with size-dependent properties. Electron oscillations in such plasma are of interest in view of resonance absorption or probing of cluster dynamics in experiments. We study the electronic oscillations via molecular dynamics simulations for interacting classical electrons and ions. In particular, surface and volume plasmons are analyzed depending on the cluster size, plasma density, the ion ordering parameter and the short range part of the interaction potential. The volume plasmons are observed only for clusters greater than a threshold cluster size. By means of GPU computing, the long-range Coulomb interactions between particles are treated without typical approximations such as PPPM or TreeMD. (paper)