Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 27: Surface Dynamics: Theory
O 27.3: Vortrag
Dienstag, 21. März 2017, 11:15–11:30, TRE Phy
Quantization of collective excitations in finite systems: An ab initio quasiparticle picture for hot carrier generation in noble metal nano clusters — •Mikael Kuisma1,2, Tuomas Rossi3, and Paul Erhart2 — 1University of Jyväskylä, Jyväskylä, Finland — 2Chalmers University of Technology, Gothenburg, Sweden — 3Aalto University, Helsinki, Finland
Resolving hot electron generation from coherent collective plasmon excitations in nanoparticles is a vital step in understanding a wide variety of physical processes. However, in order to facilitate a quantitative understanding of hot electron generation, a physically sound picture of collective excitations in nanoparticles must be established.
In our time-dependent density functional theory and many body perturbation theory based framework we extract the collective coordinates of plasmons in the electron-hole space. We find that a discrete, topology dependent number of electron-hole pairs is collectively involved in formation of a plasmon. The collective coordinates define the bare plasmons, which are further renormalized due to other electron-hole excitations via the plasmon self energy. The emerging quasiparticle picture is able to explain the plasmon renormalization due to Landau scattering and d-band screening in noble metal nanoparticle with unprecedented simplicity in reasoning and intuition, while maintaining the ab initio quantitative nature of the calculation. In order to demonstrate our approach, we analyze hot-electron generation rates in gold clusters.