Crossover of exciton-photon coupled modes in a finite system
Phys. Rev. B 80, 125319 – Published 18 September, 2009
DOI: https://doi.org/10.1103/PhysRevB.80.125319
Abstract
An exciton and a photon behave as a polariton in macroscopic materials while they can be treated almost independently in nanostructured ones. We have theoretically investigated the crossover of exciton-photon coupled modes, each of which is characterized with a resonance frequency and a radiative decay rate, in a semiconductor film by continuously increasing the thickness. The resonance frequency and the radiative decay rate are calculated from poles of exciton correlation functions renormalizing the exciton-photon interaction in the film, and we also introduce an intuitive calculation method with considering additional boundary conditions in order to derive the crossover condition. The general properties of the coupled modes are analytically discussed by the intuitive method.