# A near-field study on the transition from localized to propagating plasmons on 2D nano-wedges

## TL;DR

This study investigates how plasmonic behavior in 2D gold nano-wedges transitions from localized to propagating modes as size increases, using advanced microscopy and computational methods, revealing the coexistence of both modes in certain structures.

## Contribution

It provides new insights into size-dependent plasmonic transitions and demonstrates the ability of nano-wedges with grooves to support both localized and propagating plasmons.

## Key findings

- Transition from localized to propagating plasmons with increasing size
- Nano-wedges with grooves support both plasmon types in the same energy range
- Use of electron energy loss spectroscopy and simulations to analyze plasmon modes

## Abstract

In this manuscript we report on a near-feld study of two-dimensional plasmonic gold nano-wedges using electron energy loss spectroscopy in combination with scanning transmission electron microscopy, as well as discontinuous Galerkin time-domain computations. With increasing nano-wedge size, we observe a transition from localized surface plasmons on small nano-wedges to non-resonant propagating surface plasmon polaritons on large nano-wedges. Furthermore we demonstrate that nano-wedges with a groove cut can support localized as well as propagating plasmons in the same energy range.