Localized exciton states with giant oscillator strength in quantum well in vicinity of metallic nanoparticle

Effects of the resonant interaction between an exciton in a semiconductor quantum well and localized plasmon excitations in a spherical metal nanoparticle are studied. The calculations show that (1) if the exciton energy level is lower than the energy of the plasmon, the exciton-plasmon interaction may result in the localization of the exciton as a whole in the vicinity of the nanoparticle; (2) a giant (by several orders of magnitude) increase in the oscillator strength of the localized exciton transition takes place near the resonance between the exciton and the plasmon levels. The energy of the lowest excited level of the system was calculated by the variational method, the dependence of the localized exciton energy on the distance between the particle, and the quantum well as well as on the particle radius was obtained.