Hybrid Quantum Dot-Metal Nanoparticle Systems: Connecting the Dots

Hybrid molecules formed by coupling semiconductor quantum dots (SQD) to metal nanoparticle (MNP) nanoantennas provide a new paradigm for directed nanoscale transfer of quantum information and new building blocks to exploit in making metamaterials. To assess these possibilities, we study theoretically the response of these hybrid molecules to applied optical fields. Quantum-coherent time-evolution of the SQDs in the hybrid molecule is found by solving the SQD density matrix equations. We study hybrid molecules in the weak and strong coupling regimes. In strongly driven, strongly dipole-coupled SQD-MNP hybrids with spherical MNPs, interference, dispersion near resonance and self interaction define the MNP/SQD coupling and lead to Fano resonances, exciton induced transparency, suppressed SQD response and bistability. More complicated response can be tailored by using MNP shape and the placement of SQDs to control the local near-fields that couple the MNPs and SQDs. We describe how coupling to MNP dark modes and higher order multipolar modes impact interference and self-interaction effects. The physics of the MNP/SQD coupling is outlined and its impact on the optics of these structures is discussed.