Electron Diffraction by Plasmon Waves

TL;DR

This paper demonstrates that electron beams interacting with structured plasmonic fields undergo diffraction, revealing new effects in electron-plasmon interactions with potential for advanced optical and quantum applications.

Contribution

It introduces the concept of electron diffraction by plasmon waves, including the effects of elastic and inelastic scattering, and predicts significant diffraction patterns in realistic setups.

Findings

Diffraction patterns depend on plasmon exchange parity.

Large diffraction fractions are achievable with realistic plasmon intensities.

New effects related to electron wave function components are identified.

Abstract

An electron beam traversing a structured plasmonic field is shown to undergo diffraction with characteristic angular patterns of both elastic and inelastic outgoing electron components. In particular, a plasmonic {\it grating} (e.g., a standing wave formed by two counter-propagating plasmons in a thin film) produces diffraction orders of the same parity as the net number of exchanged plasmons. Large diffracted beam fractions are predicted to occur for realistic plasmon intensities in attainable geometries due to a combination of phase and amplitude changes locally imprinted on the passing electron wave. Our study opens new vistas in the study of multiphoton exchanges between electron beams and evanescent optical fields with unexplored effects related to the transversal component of the electron wave function.