中文摘要：

基于含时密度泛函理论,研究了环形石墨烯纳米结构的等离激元激发.在低能共振区,和同尺度大小的石墨烯纳米结构相比,环形石墨烯纳米结构光谱的主要吸收峰发生了红移;体系中有两种主要的等离激元共振模式：低能成键模式和高能反键模式.此外,环形石墨烯纳米结构的等离激元激发对体系尺度的大小也有一定的依赖性.

英文摘要：

The plasmon excitation in ring graphene nanostructures is studied by time-dependent density functional theory.In lower-energy resonance region,compared with the same size graphene nanostructure,the main absorption peak of spectra of ring graphene nanostructures shows redshift.There are two main plasmon resonance modes,the low-energy bonding mode and high-energy anti-bonding mode,in ring graphene nanostructures.Moreover,to a certain extent,the plasmon excitation in ring graphene nanostructures depends on the size of the system.