红外同步辐射条件下石墨烯等离结构系统的太赫兹光电物理特性研究

In the terahertz (THz) regime, graphene are proposed as an ideal material to investigate the advanced optoelectronic properties of two-dimensional electron gas. Based on the developed THz time-domain spectroscopy (THz-TDS) technology and the advanced features of the Hefei synchrotron radiation system, e.g. tunable-wavelength band, high brightness, and high beam quality, etc., we will design and establish an infrared synchrotron radiation pump and THz-TDS probe system (ISRP-TPS) to investigate the optoelectronic properties of graphene plasmonic structure systems (GPSS) in the presences of infrared synchrotron radiation and THz pulse at low temperature. The main content of this project is listed as follows: (1) The ISPR-TPS proposed here can perform measurements under multi-physics (including infrared synchrotron radiation, THz pulse, and low temperature). It will be initiative in the world. (2) The real and imaginary parts of the THz conductivity of monolayer graphene under synchrotron radiation pumping will be obtained by ISRP-TPS. Furthermore, the interactions between the infrared photons, THz photons, electrons, and phonons in graphene will be investigated. (3) By tuning the temperature and/or features (e.g. wavelength, intensity, and polarization, etc.) of the synchrotron radiation, new physical phenomena of three classes of GPSS proposed in this project will be studied. We will reveal the mechanism of these physical effects associating with graphene plasmons in these graphene plasmonic structure systems.

石墨烯是研究二维电子气独特光电物理特性的理想材料。基于我国大科学装置——合肥同步辐射的宽谱可调、高亮度和高光束质量等特点，结合近年来发展的太赫兹时域光谱（THz-TDS）技术，本项目提出搭建“红外同步辐射-太赫兹时域光谱探测”平台，并对石墨烯等离结构系统（GPSS）在低温、红外同步辐射及THz脉冲综合作用下的光电物理特性展开深入研究。主要研究内容包括：（1）搭建集同步辐射、THz-TDS测量、低温变温于一体的首创实验平台，实现多物理场条件下的综合测量功能，提升合肥同步辐射装置的应用技术水平和拓展装置应用领域；（2）研究石墨烯在红外同步辐射条件下的THz光电导率实部和虚部，并探索石墨烯中红外光子、THz光子、电子、声子等的交互作用机理；（3）研究三类GPSS在红外同步辐射作用下的新物理现象，获得相关光电特性随温度和红外同步辐射光性质（波长、偏振态、强度等）的变化规律，揭示其中的物理机理。

石墨烯是研究二维电子气独特光电物理特性的理想材料。基于我国合肥同步辐射（SR）装置，结合太赫兹时域光谱（THz-TDS）技术，本项目搭建了“红外同步辐射-太赫兹时域光谱探测系统”，并对石墨烯等离结构系统（GPSS）在低温、红外同步辐射及THz脉冲综合作用下的光电物理特性进行了深入研究。主要研究内容和重要结果包括：（1）完成了红外同步辐射-太赫兹时域光谱探测系统，该系统能实现变温红外测量、变温THz-TDS测量、光泵浦-THz探测、SR泵浦-THz探测等功能；（2）研究了石墨烯光电导率及其随温度和泵浦光特性的变化，并论证了石墨烯的光控THz布儒斯特效应；（3）研究了几种GPSS等离特性及其随温度和泵浦光特性的变化，论证了其物理机制；（4）依托搭建的系统和发展的理论模型，进行了相关拓展研究，如二维半导体的激子饱和行为、hBN的THz波段光Hall效应等。所得结果不仅拓展了同步辐射装置的测量功能，还在石墨烯为代表的二维材料、拓扑材料领域获得了一系列原创成果。