金属纳米颗粒结构中受限光场与量子点强耦合相互作用理论研究

In this project, we will investigate the realization and modulation of the strong coupling interactions between solid state quantum dots and the confined optical field in the metallic nanoparticle structures with surface plasmon resonances. By combining the theoretical analysis and numerical simulations, we will reveal the evolution kinetics, quantum emission characteristics and quantum interface characteristics in these systems under the strong coupling condition. We will optimize the metallic nanoparticle structures with surface plasmon enhancement characteristics, and try to achieve the strong coupling between single solid state quantum dot and the confined optical field in these structures. We will analyze the influence of the bright modes and dark modes in the confined optical field to the strong coupling interactions, and try to obtain the emission spectra with vacuum Rabi splitting that can be observed in far field. Under the condition that the strong coupling is achieve between the optical filed and multiple quantum dots or single quantum dots with multiple energy levels, we will also investigate the quantum interference kinetics of the system with accurate equations and try to achieve strong quantum interference effect. The research results will open new thoughts for the modulation of the strong coupling interactions inside the solid state quantum systems, and provide theoretical guide for the further application of the metallic nanoparticle structures in the quantum information processing.

本项目通过理论分析和数值模拟相结合，研究固态量子点与金属纳米颗粒结构中的受限光场的强耦合相互作用的实现和调控，揭示这种特定体系在强耦合条件下的演化动力学、量子辐射特性和量子相干特性。本项目试图通过对具有表面等离激元共振增强特性的金属纳米颗粒结构的优化设计，使单个固态量子点与金属纳米颗粒结构的受限光场实现强耦合。我们将分析受限光场中的各种明模式和暗模式对强耦合相互作用的影响，并在理论上得到可在远场观测的真空Rabi劈裂谱。本项目还将在多个量子点或单个多能级量子点与光场强耦合的情况下，用严格的方程研究体系的量子相干动力学，以实现强的量子相干效应。本项目的研究成果将为固态量子系统中的强耦合相互作用的量子调控提出新思路，并为金属纳米颗粒结构在量子信息领域的进一步应用提供理论指导。

实现量子电子体系与光场的强耦合相互作用，从而克服环境造成的退相干效应，是实现固态量子信息的存储、传递和处理的关键。在由微纳结构和量子点组成的固态系统中，受限光场与量子点的强耦合的实现，要求光场与量子点相互作用的耦合强度接近或超过两者自身的衰减速率。本项目通过理论分析和数值模拟相结合，研究固态量子点与金属纳米颗粒结构中的受限光场的强耦合相互作用的实现和调控，揭示这种特定体系在强耦合条件下的演化动力学、量子辐射特性和量子相干特性。本项目的研究构建了多激子与单个表面等离激元模式耦合相互作用的全量子理论，给出了简洁的实现强耦合作用的“量子光学极限条件”。依据该理论，把单个J-aggregate激子与单根银包金纳米方棒之间的耦合作用强度推向强耦合区，实验中在室温下成功观测到1-7个激子与单个等离激元纳米方棒的强耦合相互作用。本项目的研究者还构建了表面等离激元与光学微腔杂化的微纳体系，从而成功利用两者的优点，同时实现小的模体积与高Q因子的体系，为未来在该类系统中实现强耦合相互作用铺平了道路。本项目的研究成果为实现常温下的固态量子器件提供了新的思路。