中文摘要：

金属纳米粒子的表面等离激元增强效应是纳米科学领域的一个研究热点。针对染料分子与金属纳米粒子的耦合系统，应用偶极-偶极近似计算分子与金属纳米粒子的库仑相互作用，并应用密度矩阵理论描述在不同极化方向的电场作用下的电荷输运过程，分析了分子与金属纳米粒子在不同相对位置下分子激发态的动力学过程，发现表面等离激元的增强效应与分子和金属钠米粒子的相对位置以及等离激元的耗散系数有密切关系，详细讨论了分子与金属纳米粒子间的耦合强度、外场的极化方向、等离激元的寿命及共振激发条件对分子激发态及表面等离激元增强的影响，分析了分子-金属纳米粒子耦合系统中表面等离激元增强效应的物理本质。

英文摘要：

Enhancement effect of surface plasmon in the metal nano-particle is a hot topic in nano-material field. A system is investigated where a spherical metal nano-particle is placed near a dye molecule. Under the optical excitation of a polarized electric field the subsequent charge transfer dynamics for different relative positions are simulated by density matrix theory approach, where the Coulomb interaction of molecule and metal nano-particle is calculated in the frame-work of the dipole-dipole approximation. It is found that the enhancement effect is closely related to the relative distance between the molecule and metal nano-particle. Effect of enhancement due to the surface plasmon is discussed in detail for various coupling interactions, polarization of field, lifetime of plasmon, and non-resonant excitation;and the physical essence in the molecule-metal nano-particle coupled system is analysed.