中文摘要：

采用紧束缚模型研究了纳米结构原子链系统的等离激发,利用量子响应理论得出了等离激元的本征频率方程,并数值计算了该体系中等离激元的能谱,讨论了能谱对系统尺度和电子密度等的依赖关系.结果表明：（1）同等尺度下,等离子体的激发能量总是比同一级的单电子激发能量大；（2）等离激元的能谱与原子链的长度和电子密度以及系统的库仑关联强度密切相关；（3）在原子链长度保持不变的情况下,等离子体的激发能量随电子数目的变化以半满为中心呈对称关系,这表明体系中的等离激元对于电子和空穴是对称的.

英文摘要：

Plasmonic excitations in atomic chains of nanostructure are investigated by employing tight-binding model. Based on the quantum response theory, a plasma oscillation eigen-frequencies equation is derived to calculate the plasmon energy spectrum. The plasmon energy spectrum has been numerically calculated, and the dependence of plasmonic excitation energy on length of systems and electron density have been discussed. The results suggest that： （1） the plasmonic excitation energy is greater than the single-particle excitation state of same level~ （2） the length of atomic chains, the electron density and the strength of Coulomb correlation have significant effects on the plasmon spectroscopy; （3） for the given atom-chain length, with variation of number of electrons, the excitation energy of plasma varies symmetrically around the half-filling. It indicates that the plasmon in the system is symmetrical for the electrons and holes.