Light-Forbidden Transitions in Plasmon-Emitter Coupling

TL;DR

This paper explores how light-forbidden exciton transitions, such as quadrupolar states, influence the dynamics and spectral features of hybrid plasmon-emitter systems, revealing conditions that significantly alter their optical responses.

Contribution

It provides a fully analytical model for plasmon-exciton coupling involving both dipolar and quadrupolar exciton transitions, highlighting their impact on system behavior.

Findings

Quadrupolar (dipole-inactive) states can significantly modify Purcell enhancement.

Presence of light-forbidden transitions alters Rabi splitting.

Analytical description enables precise control of plasmon-exciton interactions.

Abstract

We investigate the impact that light-forbidden exciton transitions have in the near-field population dynamics and far-field scattering spectrum of hybrid plasmon-emitter systems. Specifically, we consider a V-type quantum emitter, sustaining one dipolar and one quadrupolar (dipole-inactive) excited states, placed at the nanometric gap of a particle-on-a-mirror metallic cavity. Our fully analytical description of plasmon-exciton coupling for both exciton transitions enables us to reveal the conditions in which the presence of the latter greatly alters the Purcell enhancement and Rabi splitting phenomenology in the system.