Optical susceptibility of metal nanoparticle-double quantum dot hybrid system

Abstract

This work is modeling the linear optical susceptibility of a double quantum dot (DQD)–metal nanoparticle (MNP) hybrid system using density matrix equations that consider the interaction between excitons and surface plasmons. The wetting layer (WL)-QD interaction is considered.The absorption of the hybrid DQD-MNP system increases by five times compared to the bare DQD system. The absorption peak is reducing in a similar ratio of increasing MNP radius. A Mollow triplet with asymmetric sidebands appears and decreases with increasing MNP radius, which is compatible with recent experimental evidence. The susceptibility peaks at resonance for a small distance between the hybrid MNP-DQD. The susceptibility is increased by one order for the DQD system compared to a single QD. A similar result is obtained under WL-QD detuning compared to the case of the probe between DQD states. Small DQDs give high absorption and dispersion, offering more shifts from resonance.