Strong multipolar transition enhancement with graphene nanoislands

Abstract

During the past half century, a major approximation was natural in the field of light-matter interaction: the point-dipole model. It was assumed that the wavelength is much larger than the size of the emitting atom or molecule, so that the emitter can be described as a single or a collection of elementary dipoles. As it is legitimate for visible light, the approximation does no longer hold near plasmonic nanostructures, where the effective wavelength can drop below 10 nm. In that case deviations arise from the approximate model. First, the emitter spatial extent influences the far-field spectrum. Second, high-order transitions beyond the dipolar ones are not forbidden anymore. Going beyond the approximation requires intensive numerical efforts to compute the photonic response over the spatial extent of the emitter, since the complete Green's function is required. Here, we develop a general model that computes the multipolar transition rates of a quantum emitter in a photonic environment, by computing the Green's function through an eigenpermittivity modal expansion. We apply the method on graphene nanoislands, and we demonstrate a local breakdown of the selection rules, with quadrupolar transition rates becoming 100 times larger than dipolar ones.

21 pages and 8 pages supplementary information

References in corpus (13)

• Electric Field Effect in Atomically Thin Carbon Films
• Optical properties of graphene
• Highly confined low-loss plasmons in graphene-boron nitride heterostructures
• Controlling electron-phonon interactions in graphene at ultra high carrier densities
• Space-time dispersion of graphene conductivity
• Enhanced Strong Interaction between Nanocavities and p-shell Excitons Beyond the Dipole Approximation
• Interaction of OAM light with Rydberg excitons: Modifying dipole selection rules
• Enhancement of and interference among higher order multipole transitions in molecules near a plasmonic nanoantenna
• Two-photon spontaneous emission in atomically thin plasmonic nanostructures
• Overcoming the bottleneck for quantum computations of complex nanophotonic structures: Purcell and FRET calculations using a rigorous mode hybridization method
• An efficient solver for the generalized normal modes of non-uniform open optical resonators
• Interaction of atomic systems with quantum vacuum beyond electric dipole approximation
• Light-matter interaction of a quantum emitter near a half-space graphene nanostructure