Dispersion relation due to plasmon excitation in nanostructures by charged particles

One of the most remarkable features of nanostructured materials is that their optical response due to plasmon excitation is very sensitive to their geometry and composition. The interaction of charged particles with the electron gas of the considered system is one of the most used methods to excite and study collective excitations (plasmons). In this work we study the similarities and differences arising in these excitations due to the interaction of the charged particles with different dielectric functions in a variety of nanoscopic systems (capillaries, wires, tubules, spheres). The obtained dispersion relations are very sensitive to the chosen dielectric functions, an important aspect due to the increasing requirement of devices of reduced dimensions for their application in different areas.