Strong multipolar transition enhancement with graphene nanoislands

For a long time, the point-dipole model was central and natural approximation in field of photonics. This approach assumes that wavelength is much larger than size emitting atom or molecule so emitter can be described as single collection elementary dipoles. no longer holds near plasmonic nanostructures, where effective reach nanometer-scale. In case, deviations arise high-order transitions, beyond dipolar ones, are not forbidden anymore. Typically, this situation requires intensive numerical efforts to compute photonic response over spatial extent wavefunctions. Here, we develop an efficient general for multipolar transition rates quantum environment by computing Green’s function through eigen permittivity modal expansion. A major benefit position material swept rapid way. To illustrate, apply method on various forms graphene nanoislands, demonstrate local breakdown selection rules, with quadrupolar becoming 100 times ones.