Plasmonic Edge, Centre and Breathing Modes in Two-Dimensional Disks

Recently, plasmonic edge and breathing modes are obtained by electron energy loss spectroscopy in aluminum nanotriangles and silver nanodisks. In this article, based on the free-electron gas model and the linear response theory, we have derived the energy absorption spectrum and charge distributions under applied external fields to study the plasmons sustained by two-dimensional disks. Plasmonic edge, center and breathing modes are further observed by the charge distributions. In addition, with the help of energy absorption spectrum, the evolutionary characteristics of plasmon modes with the system parameters such as size, atomic separation and electron filling are further confirmed, and the effect of different applied external fields on plasmon excitations is displayed.