Atomistic ab initio study of optical excitations in nanoplasmonic systems as probed by light and fast electrons

• Autores: Bruno Candelas Peñalba
• Directores de la Tesis: Nerea Zabala Unzalu (dir. tes.), Javier Aizpurua Iriazabal (codir. tes.)
• Lectura: En la Universidad del País Vasco - Euskal Herriko Unibertsitatea ( España ) en 2025
• Idioma: inglés
• Programa de doctorado: Programa de Doctorado en Física de Nanoestructuras y Materiales Avanzados/Physics of Nanostructures and Advanced Materials por la Universidad del País Vasco/Euskal Herriko Unibertsitatea
• Menciones:
  • Internacional
• Calificación: Sobresaliente Cum Laude
• Enlaces
  • Tesis en acceso abierto en: ADDI
• Resumen

  • This thesis presents theoretical and numerical investigations of light-matter interactions at the nanoscale within an atomistic ab initio framework. The goals set forth in the thesis encompass describing how atomistic effects at the nano- and pico-scales manifest themselves in the optical response of canonical nanoplasmonic systems when probed with light or fast electrons. The specific systems studied in the thesis are (i) a hybrid system consisting of a dimer of silver clusters coupled to an organic molecule in the strong coupling regime; (ii) isolated sodium nanoparticles probed by fast electrons in electron energy loss spectroscopy; and (iii) self-assembled monolayers of organic molecules on gold surfaces. These systems are respectively explored through the analysis of the signal from absorption optical spectroscopy (i), electron energy-loss spectroscopy (ii), and surface-enhanced Raman spectroscopy (iii). The optical response of the aforementioned configurations is computed with different density functional theory (DFT) and its time-dependent variant (TDDFT) atomistic codes, which allows for accurately capturing how aspects of the microscopic scale influence the overall spectral signal. These simulations, whose main aim is to account for atomistic and quantum effects, are supplemented by classical models to provide further qualitative understanding, and by an extensive theoretical background and appendices explaining the relevant concepts and techniques.