Welcome to Linnaeus Physics Colloquium, a series of seminars delivered by renowned researchers in physics.
Title: Shape plasmonics, geometric eigenvalues and crystal field theory
Lecturer: Stefano A Mezzasalma, Ruder Boskovic Institut, Zagreb, Croatia
Place: Kalmar: room Vi2010, building Vita. Live: https://lnu-se.zoom.us/j/416290322.
Coffee and buns will be served.
Abstract
A smooth sphere-to-cube transition is experimentally, computationally and theoretically studied in plasmonic Au nanoparticles, including the statistical analysis of particle polydispersity and shape, the electrochemistry of excess (surface) charges.
Sphere, cube and semicubes in between all show well-defined secular electrostatic eigenvalues, producing a wealthy of topological modes afterwards quenched by charge relaxation processes.
The way both eigenvalues and plasmon wavelength vary as a function of a shape descriptor, parametrizing the transition, is explained by a minimal model based on the key concepts of crystal (or ligand) field theory, bringing to an electromagnetic analog of crystal field splitting.
Expressions for non-retarded and retarded plasmon wavelengths are given and succesfully applied to both experimental UV-Vis and numerically simulated values. This analogy can be promising to delve into the role of shape in nanoplasmonics and nanophotonics.
