电子注激励石墨烯表面等离子体激元的研究  

Study on the Electron Beam Excitation of Graphene Surface Plasmon Polartions

作　　者：龚森[1,2] 胡旻[1,2] 钟任斌[1,2] 陈晓行[1,2] 张平[1,2] 赵陶[1,2] 刘盛纲[1,2] 

机构地区：[1]电子科技大学物理电子学院太赫兹研究中心,成都610054 [2]太赫兹科学协同创新中心,成都610054

出　　处：《电子科技大学学报》2016年第1期71-76,共6页Journal of University of Electronic Science and Technology of China

基　　金：国家重点基础研究发展计划(2014CB339801);国家自然科学基金(61231005;11305030;61211076);国家高技术研究发展计划(2011AA010204)

摘　　要：对垂直与平行运动电子注激励石墨烯表面等离子体激元进行了详细分析与对比。理论分析与数值计算的结果表明,电子注垂直激励时,石墨烯表面等离子体激元包含丰富的频率分量,沿传播方向衰减,并伴随有度越辐射;平行激励时,其工作频率可通过调节电子注能量或石墨烯化学势进行调谐,且沿传播方向没有衰减,没有渡越辐射。优化电子注能量与石墨烯化学势等参数可使电子注激励的石墨烯表面等离子体激元具有最大功率。电流密度大于500 A/cm2的直流电子注可与石墨烯表面等离子体激元发生注波互作用,从而对其进行持续地激励并放大。Graphene surface plasmon polaritons have been widely used in terahertz devices in modem science and technologies. In this paper, the excitation of graphene surface plasmon polaritons by perpendicularly and parallel moving electron beams is investigated in details by using Maxwell equations and boundary conditions. The theoretical analysis and numerical calculations show that graphene surface plasmon polaritons excited by perpendicular electron beam contain plenty of frequency components which attenuate along with propagation, whereas those excited by parallel electron beam are coherent and ttmable, without attenuation along with propagation. The largest power of the excited graphene surface plasmon polaritons can be obtained by optimizing the electron beam energy and the chemical potential of the graphene sheet. And the further study show that graphene surface plasmon polaritons can be excited and amplified by continually moving electron beam when the current density of the beam is large enough. These results are of significance for the applications of graphene in terahertz devices.

关 键 词：电子注 石墨烯 表面等离子体激元 太赫兹 频率调谐 

分 类 号：TN201[电子电信—物理电子学]