Electrodynamics of semiconductor-coated noble metal nanoshells

Abstract

The full Maxwell equations for a system of concentric shells of a noble metal and a semiconductor, with a very sharp excitonic resonance with a bare frequency in the gap between the bare plasmonic resonant frequency branches and having a strong oscillator strength, are solved. The plasmon-exciton coupling model is verified to produce for this dressed plexcition a spectrum that consists of a splitting of the bare excitonic resonance into two daughters and a shift in the plasmonic resonances from their bare values. The spectral region separating the excitonic daughters exhibits the features characteristic of induced transparency and slow light propagation. Furthermore, I show that the eigenvalues of this coupled system as herein are computed to significantly differ from those obtained in the electrostatic approximation where retardation and radiation reaction terms are neglected.