Pump-probe optical response of semiconductor quantum dot-metal nanoparticle hybrids

We study optical effects in a hybrid system composed of a semiconductor quantum dot (SQD) and a spherical metal nanoparticle (MNP) that interacts with a weak probe and a strong pump electromagnetic field. We use modified nonlinear density matrix equations for the description of the optical properties of the system and calculate, numerically, the first-order susceptibilities of the SQD, the MNP, and the total hybrid nanostructure of the probe field in the presence of the pump field. We investigate the dependence of the probe absorption and dispersion spectra of the SQD, the MNP, and the total nanostructure on the interparticle distance and the detuning of the pump field, and stress the influence of the MNP contribution to the total optical response. The results we find are explained according to the theory of two distinct metastates, which constitute conjugations of the SQD excitonic and the MNP plasmonic excitations. We also show that the optical response strongly depends on the actual values of the SQD material parameters. Published by AIP Publishing.