The effect of quantum correction for the dielectric function on the optical properties of a plasmon–exciton–plasmon hybrid system

In this paper, the optical properties of two small silver metallic nanoparticles (sAgNPs) coupled to a quantum dot (QD) are studied. The interaction between sAgNP and QD is investigated theoretically using the compact density matrix method. In this paper, due to the small size of the AgNP, the dielectric function does not follow the classical models and quantum-size effects must be considered. The excitation of surface plasmons in sAgNP is observed using the finite element method. The main result of the current study shows that when AgNPs are small, the absorption spectrum profile of the QD is strongly affected due to the plasmon–exciton–plasmon interaction. The absorption spectrum profile of the QD shows an electromagnetically induced transparency with two peaks and a minimum in the transition frequency. Then, the near-field enhancement of the sAgNP, the field experienced by the QD, the exciton transition energy shift, and the Forster-enhanced broadening of the excitonic transition are also examined.