This seminar reviews ongoing experimental and theoretical efforts to explore the plasmonic response in metallic nanoparticles, where nanometric dimensions are expected to promote a nonlocal plasmonic response beyond that of the usual classical electrodynamics. I will review efforts in semi-classical hydrodynamic extensions to classical electrodynamics [1,2], as well as our most recent developments beyond these simplified models [3,4]. I will also address recent single-particle electron energy-loss spectroscopy (EELS) observations of higher-order modes in silver nanoparticles [5]. Beyond the more fundamental aspects I will also discuss applications of nanoplasmonic systems, where localized plasmon resonances are used to facilitate a broad range of plasmonic colours with applications in decoration of plastic surfaces [6] and with novel opportunities for laser-post processing and printing of colours with subwavelength resolution [7].
[1] N.A. Mortensen, S. Raza, M. Wubs, T. Søndergaard, and S.I. Bozhevolnyi, "A generalized non-local optical response theory for plasmonic nanostructures", Nature Communications 5, 3809 (2014)
[2] S. Raza, S.I. Bozhevolnyi, M. Wubs, and N.A. Mortensen, "Nonlocal optical response in metallic nanostructures", J. Phys. Cond. Matter. 27, 183204 (2015)
[3] G. Toscano, J. Straubel, A. Kwiatkowski, C. Rockstuhl, F. Evers, H. Xu, N. A. Mortensen, and M. Wubs, "Resonance shifts and spill-out effects in self-consistent hydrodynamic nanoplasmonics," Nature Communications 6, 7132, (2015)
[4] W. Yan, M. Wubs, and N. A. Mortensen, "Projected-dipole model for quantum plasmonics," "Projected Dipole Model for Quantum Plasmonics", Phys. Rev. Lett. 115, 137403 (2015)
[5] S. Raza, S. Kadkhodazadeh, T. Christensen, M. Di Vece, M. Wubs, N.A. Mortensen, and N. Stenger, "Multipole plasmons and their disappearance in few-nanometer silver nanoparticles", Nature Communications 6, 8788 (2015)
[6] J. Clausen, E. Hojlund-Nielsen, A. Christiansen, S. Yaszdi, M. Grajower, H. Taha, U. Levy, A. Kristensen, and N.A. Mortensen, "Plasmonic metasurfaces for coloration of plastic consumer products", Nano Lett. 14, 4499 (2014)
[7] X. Zhu, C. Vannahme, E. Hojlund-Nielsen, N.A. Mortensen, and A. Kristensen, "Plasmonic colour laser printing", Nature Nanotechnology 11, 325 (2016)