基于石墨烯的量子纳米体系表面等离激元特性与激发方式的理论研究

项目名称： 基于石墨烯的量子纳米体系表面等离激元特性与激发方式的理论研究

项目编号： No.11474207

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 张红

作者单位： 四川大学

项目金额： 80万元

中文摘要： 尺度10纳米以下石墨烯中表面等离激元在分子尺度的聚焦、粒子捕获、吸收、生物传感和疾病治疗等方面有巨大应用价值，它可以和光子、声子以及电子发生相互作用产生新奇丰富的物理现象，对其研究具有重要科学意义。在微观物理机制、波段扩展和调控方式等方面亟需在全量子水平上对其开展理论研究。本项目采用含时密度泛函理论、多体格林函数以及量子Monte Carlo等研究石墨烯量子纳米体系的等离激元特性，为等离激元研究提供基准性数据。研究体系包含平面型和层叠型石墨烯构成的阵列及其和金属纳米线、管等组成的复合结构，考虑形状、尺寸、边缘、掺杂、间距、排列方式以及激发场偏振方向等影响。采用含时密度泛函框架下的实时传播子方法研究低能运动电子激发以及表面声波辅助光激发两种激发方式下石墨烯中的电子激发动力学和等离激元性质，建立特定激发方式下局域场增强的微观动力学图象，为优化设计不同应用背景下的纳米等离激元器件提供理论指导。

中文关键词： 石墨烯；表面等离激元；电子激发动力学；量子纳米体系

英文摘要： The surface plasmon in graphene (with the size smaller than 10 nm) possesses unique properties such as broad frequency band, long lifetime and enabled control due to the quantum finite-size effect, which makes it great potential value in the application for focusing, particle trapping, absorption, biosensor, and cancer therapy at molecular scale. The surface plasmon in graphene can interact with photon, phonon and electron, and generates many marvelous physical phenomena. The surface plasmon in graphene is also a complex platform for the exploration of many-body physics. So the investigation on it has great scientific significance. Hence, it is necessary to investigate theoretically the plasmon excitation, band broadening and controlling method by using a fully quantum-mechanical method. In this project, the surface plasmon of graphene nanosystems with both stacked and planar structure will be investigated,and the hybrid structure of nanographene with metal nanowire and metal nanotube will be studied also. The quantum methods used include time-dependent density functional theory (TDDFT),many-body Green function(GW) and quantum Monte Carlo method(QMC).We will present benchmark data for the theoretical study of surface plasmon after careful checking the results obtained from using different methods.In addition, the plasmon properties especially the coupling property between graphene quantum monomer will be studied also, which can be influenced by geometry, size, edge, doping, distance between the dots and polarization direction of light. For the low energy electron moving atop the graphene, we will study the dynamic process of the electron excitation in the graphene, and the characteristic of surface plasmon, using the time-dependent density functional theory in the real-time-propagation (RTP) approach, and we try to grasp the physical nature in it. Similarly, the excited situation for surface sound wave assisted will be studied. The micro-dynamic picture of surface plasmon excitation and local field enhancement under the interaction of low energy moving electron or surface acoustic wave will be obtained. These results would provide useful information for nano-scale graphene plasmon device.

英文关键词： graphene;surface plasmon;electron excitation dynamics;quantum nano-system