Plasmon-enhanced Brillouin light scattering spectroscopy for magnetic systems. II. Numerical simulations

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 wave number of detectable spin waves and the typically relatively low sensitivity. In this paper, we present the results of numerical simulations based on the recently developed analytical model describing plasmon-enhanced BLS. 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, describing their shape, plays a leading role in enhancing 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. Published by the American Physical Society 2025