Electronic excitations, energy loss and electron emission in the interaction of charged particles with metallic materials and plasmon modes localized at surface singularities

Resumen

The works presented in this PhD thesis consist of two main subjects. The first part deals with electronic excitations, energy loss and electronic emission in the interaction of charged particles with metallic materials. It includes: quantum and classical transport cross section calculation for a screened potential, stopping power of low velocity ions in an Electron Gas beyond the asymptotic low-velocity approximation, calculation of electromigration forces on a proton in a metal, and spin polarization of electrons excited by a low velocity ion in a metal. Whereas the second part is focused on plasmonics. It is shown a new theoretical approach to determine the surface plasmon frequencies of metal surfaces, based on the shape of the metal. Applying this method, we obtain the surface plasmon frequencies in wedges, corners and conical tips. These results provide simple and straightforward rules to design and tailor the frequencies of the surface plasmons modes in severals situations of experimental interest such as in plasmon wave guiding and in tip-enhanced spectroscopies.