Angular momentum transfer from swift electrons to non-spherical nanoparticles within the dipolar approximation

Area of Science:

• Plasmonics
• Nanophotonics
• Quantum Electrodynamics

Background:

• Previous studies primarily focused on spherical nanoparticles for electron-induced angular momentum transfer.
• Understanding shape-dependent plasmonic resonances is crucial for manipulating light-matter interactions at the nanoscale.

Purpose of the Study:

• To investigate angular momentum transfer from swift electrons to non-spherical metallic nanoparticles (spheroids and Platonic Solids).
• To compare the angular momentum transfer efficiency across different nanoparticle geometries.
• To explore potential applications in advanced electron microscopy and manipulation techniques.

Main Methods:

• Utilized classical electrodynamics and the small particle limit for calculations.
• Integrated spectral density to determine angular momentum transfer.
• Employed Fourier-transform analysis to ensure causality.

Main Results:

• Prolate spheroids showed lower angular momentum transfer due to a single blueshifted resonance.
• Oblate spheroids exhibited higher transfer with both blueshifted and redshifted resonances.
• Platonic Solids with fewer faces displayed significant redshifts and higher transfer, influenced by edge effects.
• Dual Platonic Solids showed similar resonance and transfer characteristics.

Conclusions:

• Nanoparticle shape significantly influences electron-induced angular momentum transfer.
• Specific non-spherical geometries, like oblate spheroids and certain Platonic Solids, enhance angular momentum transfer.
• Findings suggest potential for applications in electron tweezers and nanoscale manipulation.