Quantum Properties Of Quantum Dot-Surface Plasmons Coupling System

Cavity Quantum Electrodynamics theory is often used to analyze the nonlinear optical properties and quantum states of point-cavity coupling systems in full quantum systems.At this stage,photonic crystals are commonly used as nanocavities to increase the interaction between light and matter.The miniaturization,integrated device is the direction and demand for the development of information technology.However,due to the existence of diffraction limits,the structure size of photonic crystal microcavity is still limited.Surface plasmons which are present on the surface of metal nanostructures can solve this problem.They can break through the diffraction limit and make the optical microcavity reach a smaller model volume.This is due to the presence of a large number of free electrons on the surface of the metal nanoparticles.These free electrons can interact with external stimuli to generate resonance waves.Due to the binding effect of the metal interface,the resonance wave propagates only on the metal surface.The research object of this paper is the quantum dot-surface plasmons coupling system.1.gold cone dimer is chosen as the model structure.We analyze the influence of different structural parameters on the absorption cross section.The results show that in the case of point cavity resonance,the concentration effect of the metal nanoparticles on the light field and its loss coefficient will not reach the optimal simultaneously.To explore the effect of these two properties on the quantum properties of the research system,we choose two typical structures as comparisons.2.analyzing the quantum properties of the model in the full quantum framework requires us to describe the model using the cavity quantum electrodynamics theory.Then eight parameters are required to solve the quantum master equation.In this paper,we combine the cavity quantum electrodynamics,which is used in the quantum electromagnetic field,and the finite element method,which is used in the classical electromagnetic field.Taking absorption cross section as intermediate medium,the corresponding parameters are obtained by fitting the absorption cross section curve under the two methods.3.we discuss the quantum properties of coupling system from the quantum states of quantum electromagnetic field.The zero-order second-order correlation function of quantum dot-surface plasmons coupling system is calculated.The calculation results show that this model can generate single photon.In order to further discuss the coupling phenomenon,we investigate the influence of resonance and detuning between quantum dots and metal nanoparticles on the absorption cross section of the coupling system.The results show that,compared with the influence of their structures,these two points have little effect on their quantum properties.