Interação radiação-matéria em pontos quânticos semicondutores em nanocavidades

Abstract

Integrating solid-state qubits to photonic circuit can be a revolutionary ingredient for quantum information processing and transportation of information. If on one hand solidstate based qubits are a very promising candidate for the quantum computation unit, photons, on the other hand, are the most reliable and fast way to transport information. Making the junction of this two ingredients is highly desired. In this sense, semiconductor quantum dots (QDs) in photonic crystals (PhC) provide a perfect environment for such an integration, where waveguides can be used to connect qubits and detectors. In this work, the light-matter interaction of a system composed of quantum dots embedded in semiconductors nanocavities is studied in details using density matrix formalism in the Lindblad form. In a first study, the effect of incoherent therms on the splitting of emission spectrum of a single QD inside a PhC is analyzed and we found that the splitting observed in the experiments can not translated very easily by polaritonic splitting. In other words, the observed splitting is not the coherent coupling between exciton and photons. In another work a quantum dot molecule inside a PhC is used and found that depending on the symmetry (symmetric or anti-symmetric) the molecule state, the splitting in the emission spectrum can be decreased (even zero depending on the choices of parameters) or enhanced when compared to that of a single QD. In the last study the emission spectrum of a system composed of an empty cavity coupled to another cavity with a single QD embedded is investigated. Our results demonstrate that the emission spectra of a low quality factor mode of the empty cavity can be used to monitor the quantum dot-cavity subsystem and its interactions.