Collective dipole excitations in sodium clusters

TL;DR

This paper investigates the collective dipole excitations in sodium clusters using RPA, calculating optical properties and plasmon frequencies, and comparing results with experimental data to validate the theoretical approach.

Contribution

It introduces a method using RPA with a projected spherical basis to analyze sodium cluster excitations and their optical properties, aligning theoretical predictions with experiments.

Findings

Good agreement between calculated and experimental photoabsorption spectra

Dependence of plasmon frequency on cluster size established

Static electric polarizabilities computed and validated

Abstract

Some properties of small and medium sodium clusters are described within the RPA approach using a projected spherical single particle basis. The oscillator strengths calculated with a Schiff-like dipole transition operator and folded with Lorentzian functions are used to calculate the photoabsorbtion cross section spectra. The results are further employed to establish the dependence of the plasmon frequency on the number of cluster components. Static electric polarizabilities of the clusters excited in a RPA dipole state are also calculated. Comparison of our results with the corresponding experimental data show an overall good agreement.