Plasmon-enhanced Brillouin Light Scattering (BLS) spectroscopy for magnetic systems. II. Numerical simulations

TL;DR

This paper uses numerical simulations to explore how plasmonic nanoparticles can enhance Brillouin light scattering signals in magnetic systems, improving detection sensitivity and wavenumber range.

Contribution

It introduces an analytical model for plasmon-enhanced BLS and identifies optimal nanoparticle shapes and materials for signal enhancement.

Findings

Eccentricity of nanoparticles significantly boosts BLS signal.

Optimal conditions identified for gold and silver plasmonic systems.

Provides a roadmap for experimental realization of enhanced BLS spectroscopy.

Abstract

Brillouin light scattering (BLS) spectroscopy is a powerful tool for detecting spin waves in magnetic thin films and nanostructures. Despite comprehensive access to spin-wave properties, BLS spectroscopy suffers from the limited wavenumber of detectable spin waves and the typically relatively low sensitivity. In this work, we present the results of numerical simulations based on the recently developed analytical model describing plasmon-enhanced BLS. The effective susceptibility is defined for a single plasmonic nanoparticle in the shape of an ellipsoid of rotation, for the sandwiched plasmonic nanoparticles separated by a dielectric spacer, as well as for the array of plasmonic resonators on the surface of a magnetic film. It is shown that the eccentricity of the metal nanoparticles, which describes their shape, plays a key role in the enhancement of the BLS signal. The optimal conditions for BLS enhancement are numerically defined for gold and silver plasmon systems for photons of different energies. The presented results define the roadmap for the experimental realization of plasmon-enhanced BLS spectroscopy.