Real-time surface plasmon polariton propagation in silver nanowires

TL;DR

This paper presents a time-dependent analysis of surface plasmon polariton propagation in silver nanowires using electron energy-loss spectroscopy, revealing detailed dynamics crucial for advanced plasmonic applications.

Contribution

It introduces a combined experimental-theoretical approach to study real-time plasmonic excitations and their interactions in silver nanowires, emphasizing azimuthal modes and dynamic behavior.

Findings

Demonstrated real-time plasmon propagation in silver nanowires

Analyzed the role of azimuthal modes in plasmonic excitations

Provided insights for designing plasmonic sensors and quantum optics applications

Abstract

Electron microscopy techniques such as electron energy-loss spectroscopy (EELS) facilitate the spatio-spectral characterization of plasmonic nanostructures. In this work, a time-dependent perspective is presented, which significantly enhances the utility of EELS. Specifically, silver nanowires offer the material and geometric features for various high-quality plasmonic excitations. This provides an ideal illustrative system for combined experimental-theoretical analyses of the different plasmonic excitations and their real-time dynamics. It is demonstrated how the plasmonic excitations propagating inside the wire repeatedly interact with the swift electrons in an EELS configuration. In addition, the role of azimuthal modes, often overlooked for very thin wires, is observed and analyzed in both the energy-loss spectrum and the dynamical perspective. Such a complete understanding of the interaction of electrons and plasmonic excitation is key for the design of efficient plasmonic sensors, the study of hot electron dynamics in metals, and applications in the context of electron quantum optics, where full control of the spatial and temporal characteristics of the fields at the nanometer and femtosecond scales is highly desirable.