Anapole-Mediated Emission Enhancement in Gallium Nitride Nanocavities

TL;DR

This paper theoretically explores gallium nitride nanocavities supporting anapole states, demonstrating enhanced emission and tunable polarization for potential ultra-compact quantum light sources.

Contribution

It introduces a novel gallium nitride nanocavity design supporting tunable anapole states for emission enhancement.

Findings

Gallium nitride nanodisks support tunable anapole states.

Anapole states enhance emission efficiency of quantum emitters.

Emission polarization can be controlled by emitter positioning.

Abstract

Benefiting from their low-loss light manipulation at subwavelength scales, optically resonant dielectric nanostructures have emerged as one of the most promising nanophotonic building blocks. Here, we theoretically conceive a dielectric nanocavity made of moderate-refractive-index gallium nitride and investigate the strong electromagnetic field confinement inside the nanocavity. We demonstrate that gallium nitride nanodisks can support anapole states, which result from interference between electric dipole and toroidal dipole modes and are tunable by changing sizes of the nanodisks. The highly confined electromagnetic field of the anapole states can promote the emission efficiency of a single quantum emitter inside the nanocavity. Moreover, the emission polarization can be tuned by placing the quantum emitter off the nanodisk center. Our findings provide a promising candidate for the construction of ultra-compact, super-radiative integrated quantum light sources.