Absorption and Dispersion Properties of a Coupled Asymmetric Double Quantum Dot Molecule–Metal Nanoparticle Structure †.

The interaction of excitons with localized surface plasmons in hybrid nanostructures containing semiconductor quantum dots and metal nanoparticles, under specific conditions, may generate products with collective optical properties that have an abundance of potential applications in the area of nanotechnology. In the present study, we explore the behavior of the linear absorption and dispersion properties of the double-semiconductor quantum dot molecule in the presence of a spherical metal nanoparticle. We find that a transparency window arises in the absorption spectrum, the width of which decreases with the decrease in the electron tunnelling rate. In the low-electron-tunnelling regime, slow light is generated, an effect closely associated with tunneling-induced transparency. The enhancement of the tunneling rate induces a broadening in the transparency window, occurring due to the Autler–Townes splitting. The investigation of the impact of the distance between the quantum dot and the metal nanoparticle on the slowdown factor and the width of the transparency window shows that, by transposing the metal nanoparticle closer to the double-semiconductor quantum dot molecule, the transparency window widens. [ABSTRACT FROM AUTHOR]