Coherent effects in energy absorption in double quantum dot molecule - Metal nanoparticle hybrids

We theoretically study the optical properties of a hybrid structure consisting of a metal nanoparticle (MNP) and an asymmetric double semiconductor quantum dot (SQD) molecule, which are coupled together, via long-range Coulomb interaction. We derive and solve numerically the relevant density-matrix equations and use electromagnetic calculations to evaluate the energy absorption rate of the MNP and the asymmetric double SQD molecule, separately, as well as, the total absorption rate for the entire hybrid structure, as a function of the energy of an applied electromagnetic field, for two different applied field polarization directions. We also investigate the impact of the applied field intensity and the electron tunnelling coupling rate on the spectral profiles, for several values of the interparticle distance. The Autler-Townes splitting and double nonlinear Fano effects are obtained in the absorption spectra of the asymmetric double SQD molecule, the MNP and the total system.

Automated summary

In this study, the optical properties of a hybrid structure composed of a metal nanoparticle and an asymmetric double semiconductor quantum dot molecule were theoretically analyzed. The effects of applied field direction, intensity, and electron tunnelling coupling on the absorption spectra were investigated, revealing Autler-Townes splitting and double nonlinear Fano effects.