Spatially resolved dynamic structure factor of finite systems from molecular dynamics simulations

Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Sep;84(3 Pt 2):036406. doi: 10.1103/PhysRevE.84.036406. Epub 2011 Sep 12.

Abstract

The dynamical response of metallic clusters up to 10(3) atoms is investigated using the restricted molecular dynamics simulations scheme. Exemplarily, a sodium like material is considered. Correlation functions are evaluated to investigate the spatial structure of collective electron excitations and the optical response of laser-excited clusters. In particular, the spectrum of bilocal correlation functions shows resonances representing different modes of collective excitations inside the nano plasma. The spatial structure, the resonance energy, and the width of the eigenmodes have been investigated for various values of electron density, temperature, cluster size, and ionization degree. Comparison with bulk properties is performed and the dispersion relation of collective excitations is discussed.