Electron-photon scattering mediated by localized plasmons: A quantitative analysis by eigen-response theory

TL;DR

This paper demonstrates that localized plasmons can significantly enhance electron-photon scattering interactions, with potential applications in plasmon detection and material characterization, supported by theoretical, numerical, and experimental evidence.

Contribution

It introduces an eigen-response theory to quantitatively analyze plasmon-mediated scattering, revealing dark plasmons can be as effective as bright ones.

Findings

Dark plasmons can produce scattering as strong as bright plasmons.

Eigen-response theory accurately predicts scattering enhancements.

Experimental verification confirms theoretical and numerical results.

Abstract

We show that the scattering interaction between a high energy electron and a photon can be strongly enhanced by different types of localized plasmons in a non-trivial way. The scattering interaction is predicted by an eigen-response theory, numerically verified by finite-difference-time-domain simulation, and experimentally verified by cathodoluminescence spectroscopy. We find that the scattering interaction associated with dark plasmons can be as strong as that of bright plasmons. Such a strong interaction may offer new opportunities to improve single-plasmon detection and high-resolution characterization techniques for high quality plasmonic materials.