Resonancia de plasmones localizados en nanopartículas metálicas

Abstract

This thesis presents a theory about the nature of plasmons with arbitrary geometry, together with the response of such systems to a spatially uniform electric field (in the direction of one axis of the particle). In the chapter 2, the quantum Hamiltoniano is used to obtain how the operators of creation and annihilation of plasmons act in the field plasmonic. In addition, it gets the status of response on the part of the electrons to the disturbance of electronic character and the effect of external fields. In Chapter 3, there are obtained lengths of the superficial plasmon in the propagation in the metal-dielectric interface of the metal-dielectric, as well as the depth of penetration of the electromagnetic wave the metal. In the chapter 4 the analysis is restricted to the quasi-static description for the resonance of spherical and egg-shaped nanoparticles using the approach dipolar, including the interaction with the atomic nuclei across the damping and with the surface. In Chapter 5 we study modes plasmonic in nanoparticle whereas “ method” as a solution to Maxwell's equations for the eigenvectors of plasmons and its eigenvalues . Using Green's functions and the optical theorem are obtained the integral equations for the field function which allows you to calculate integral expressions for the electric and magnetic field of the system. As well as to obtain the transverse coefficients of absorption, dispersion and extinction for the study of the optical properties in metallic nanoparticles. Using numerical tools, we study the effects of size and shape of the nanoparticle in the resonance of the plasmon located with spherical and ellipsoidal geometry.