cfaed Seminar Series

Due to the excitation of localized surface plasmons (LSPs), metallic nanoparticles behave like optical antennas, converting free-propagating optical radiation into localized fields and in this way strongly perturbing their surrounding electromagnetic environment. Point-like emitters located in their proximity can thus undergo important changes of their spontaneous emission rate and quantum yield, and if the interaction becomes strong enough, they can experience the alteration of the energy levels that are responsible for the emission process with the appearance of new resonant peaks in the optical response. Both these regimes of interaction, named weak and strong coupling, are presented and analyzed in the classical framework of the Discrete Dipole Approximation (DDA). The method, is applied to analytically-unsolvable geometries, e.g. sharp silver nanocones and nanodisks, demonstrating the possibility to numerically control plasmons-emitters interactions in a simple way. 

The limits of a classical description of LSP's, by entering the quantum size regime, are then put in evidence and a method to take into account quantum effects, is presented. 

Stefania D'Agostino got her Master Degree in Physics from the University of Salento in Lecce (Italy) in 2006 and received the Ph.D. Degree in Nanoscience from the ISUFI School of the University of Salento in 2010, working in the National Nanotechnology Laboratory (NNL) of CNR with a dissertation entitled "Theoretical Modeling of Plasmonic Nanosystems". From 2011 to 2013, she was Post-Doctoral Fellow in the group of Prof. L. C. Andreani at the Department of Physics of the University of Pavia (Italy). She is currently Post-Doctoral Researcher at the Center for Biomolecular Nanotechnologies of the Italian Institute of Technology (IIT) in Lecce, Lecturer of Photonics in the Department of Physics of the University of Salento and Tutor-ISUFI for the Natural Science Area. Her research interests span from solid-sate physics to nanophotonics and plasmonics and her activity is focused on the theoretical study and modeling of localized surface plasmons and their interaction with point-like emitters in both weak and strong coupling regimes. She is author of more than 20 peer-reviewed papers and co-author of the book "Handbook of Molecular Plasmonics", edited by Pan Stanford Publishing.