Optical absorption spectroscopy in hybrid systems of plasmons and excitons

Abstract

Understanding the physics of light emitters in quantum nanostructures regarding scalability, geometry, structure of the system and coupling between different degrees of freedom is important as one can improve the design and further provide rigorous controls of quantum devices. The coupling between these degrees of freedom, in general, depends on the external field, the geometry of nano particles, and the experimental design. An effective model is proposed to describe the plasmon–exciton hybrid systems and its optical absorption spectra, which is studied in detail by exact diagonalization. Two different designs are discussed: a nano particle planet surrounded by quantum dot satellites and a quantum dot planet surrounded by nano particle satellites. In both setups, details of many quantum dots and nano particles are studied, and the spectra are discussed in detail regarding the energy of transition peaks and the weight distribution of allowed transition peaks. Also, different polarization of external fields is considered, which results in anisotropic couplings, and the absorption spectra clearly reveal the difference qualitatively. Finally, the system will undergo a phase transition in the presence of attractive interactions between excitons. Our work sheds light on the design of nano scale quantum systems to achieve photon emitter/resonator theory in plasmon–exciton hybrid systems.