Dresden 2017 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 11: Plasmonics and Nanooptics I: Light-Matter Interactions
HL 11.10: Talk
Monday, March 20, 2017, 12:45–13:00, TRE Ma
A near field study on the transition from localized to propagating plasmons on 2D nano-tips — •Thorsten Weber1, 2, Thomas Kiel3, Stephan Irsen2, Kurt Busch3, 4, and Stefan Linden1 — 1Physikalisches Institut, Universität Bonn, Nußallee 12, D-53115 Bonn, Germany — 2Electron Microscopy and Analytics, Center of Advanced European Studies and Research, Ludwig-Erhard-Allee 2, D-53175 Bonn, Germany — 3Institut für Physik, Humboldt-Universität Berlin, Newtonstraße 15, D-12489 Berlin, Germany — 4Max-Born-Institut, Max-Born-Straße 2A, D-12489 Berlin, Germany
Plasmonic nano-structures have the unique capability to concentrate light in nanometric volumes. One approach to use this capability is based on resonant plasmonic nanostructures like rod nanoantennas or split ring resonators. In these resonant structures, hot spots of the electromagnetic field are created by localized particle plasmons. Another approach is utilizing non-resonant structures, such as nano-tips, on which propagating surface plasmons are excited at the wider end and travel towards the tip's apex.
Here, we report on a near field study of two-dimensional plasmonic gold nano-tips using electron energy loss spectroscopy in combination with scanning transmission electron microscopy, as well as discontinuous Galerkin time-domain calculations. With increasing nanotip size, we observe a transition from localized particle plasmons on resonant nano-tips to non-resonant propagating surface plasmons on large nano-tips. Furthermore we demonstrate that nano-tips with a groove cut can support both localized and propagating plasmons.