Title: A Jellium Pseudopotential Generator for Modelling the Plasmonic Response of Complex-shaped Nanostructures.
When: Tuesday, February 13, (2018), 12:00.
Place: Department of Theoretical Condensed Matter Physics, Faculty of Sciences, Module 5, Seminar Room (5th Floor).
Speaker: Lorenzo Stella, Atomistic Simulation Centre School of Mathematics and Physics and School of Chemistry and Chemical Engineering Queen’s University Belfast.
Experimental advances in the fabrication and control of nanometallic architectures, achieving nanometric and even sub-nanometric precision, have underlined the significance of quantum effects for systems with plasmonic functionalities, thereby challenging classical descriptions of their optical properties. In the interest of capturing both global geometrical features, as well as the intrinsically quantum nature of the electronic response at optical frequencies, we introduce a flexible jellium pseudopotential generator (JPG) for time-dependent density functional computations. We demonstrate the predictive capacity afforded by the JPG through a study of both single gold nanocubes, as well as of a sequence of morphological transformations that relate the cubic and spherical geometries. Plasmon-induced charge distributions for the cube are found to be in qualitative agreement with classical predictions, not withstanding deviations that originate in electronic delocalisation. The evolution in the absorption spectrum, during the cube-sphere transition, highlights the role of not only the polyhedral vertices, but also of the manner in which they are connected. Conclusions of this nature may bear important implications for the design of complex-shaped nanoparticles with desirable optical properties.