Strong coupling regime and hybrid quasinormal modes of a single plasmonic resonator coupled to a TMDC monolayer

TL;DR

This paper develops a rigorous model for strong light-matter coupling between a monolayer TMDC and a plasmonic nanoparticle, revealing hybrid modes with spectral splittings and Fano resonances without phenomenological assumptions.

Contribution

It introduces a three-dimensional hybrid quasinormal mode framework to accurately describe strong coupling in plasmonic-TMDC systems, surpassing traditional normal mode theories.

Findings

Spectral splittings of 80-110 meV observed

Hybrid modes exhibit Fano-like resonances

No fitting parameters used in material models

Abstract

We present a rigorous photonic mode model to describe the strong coupling between a monolayer of $\rm MoSe_2$ and a single gold nanoparticle. The onset of strong coupling is quantified by computing the three-dimensional hybrid quasinormal modes of the combined structure, allowing one to accurately model light-matter interactions without invoking the usual phenomenological theories of strong coupling. We explore the hybrid quasinormal modes as a function of gap size and temperature and find spectral splittings in the range of around 80-110 meV, with no fitting parameters for the material models. We also show how the hybrid modes exhibit Fano-like resonances and quantify the complex poles of the hybrid modes as well as the Purcell factor resonances from embedded dipole emitters. These effects cannot be described with the usual heuristic normal mode theories.