Real-space imaging of nanotip plasmons using electron energy loss spectroscopy

Abstract

We report the spatial mapping of surface plasmons on conical gold nanotips by electron energy loss spectroscopy. We observe standing-wave patterns resulting from reflections of the fundamental surface-plasmon mode at the nanotip apex. The experimental results are in very good agreement with numerical calculations using the discontinuous Galerkin time-domain method and analytical computations based on a cylindrical mode expansion.