# Magnetic and Electric Mie-Exciton Polaritons in Silicon Nanodisks

## TL;DR

This paper demonstrates strong light-matter coupling in silicon nanodisks with both electric and magnetic resonances, revealing potential for advanced control in nanophotonics and quantum optics.

## Contribution

It provides the first experimental and theoretical evidence of strong coupling involving both electric and magnetic dipole resonances in silicon nanodisks.

## Key findings

- Strong coupling observed between silicon nanodisk resonances and organic semiconductor.
- Energy splittings comparable to plasmonic systems.
- Distinct coupling strengths for electric and magnetic resonances.

## Abstract

Light-matter interactions at the nanoscale constitute a fundamental ingredient for engineering applications in nanophotonics and quantum optics. To this regard electromagnetic Mie resonances excited in high-refractive index dielectric nanoparticles have recently attracted interest because of their lower losses and better control over the scattering patterns compared to their plasmonic metallic counterparts. The emergence of several resonances in those systems results in an overall high complexity, where the electric and magnetic dipoles have significant overlap in the case of spherical symmetry, thus concealing the contributions of each resonance separately. Here we show, experimentally and theoretically, the emergence of strong light-matter coupling between the magnetic and electric-dipole resonances of individual silicon nanodisks coupled to a J-aggregated organic semiconductor resonating at optical frequencies, evidencing how the different properties of the two resonances results in two different coupling strengths. The energy splittings observed are of the same order of magnitude as in similar plasmonic systems, thus confirming dielectric nanoparticles as promising alternatives for localized strong coupling studies. The coupling of both the electric and magnetic dipole resonances can offer interesting possibilities for the control of directional light scattering in the strong-coupling regime and the dynamic tuning of nanoscale light-matter coupled states by external fields.