THz and subTHz Excitations in Graphene Based Materials:Magneto-Optical Studies

本项目旨在详细了解石墨烯基材料的低能电子结构，这些材料是通过不同的方法制备的，如外延生长、CVD、剥离或从块石墨解耦的石墨烯。这将通过在太赫兹和次太赫兹区域的磁光研究来完成，分别使用红外和高频电子顺磁共振光谱仪，在频率和磁场领域。我们提出了第一个系统的比较研究石墨烯样品，不同的衬底，缺陷，尺寸和晶界等。无创低能（0.4-40 meV）实验方法将带来关于本征电荷迁移率极限、电子能带结构（费米表面）和其他现象（如受限等离子体、磁激发等）的决定性信息。低能激发将作为层数的函数来跟踪，以绘制和理解从单层石墨到块状石墨的电子特性变化。我们还将在门控石墨烯薄片中进行首次微波磁吸收测量，目的是控制受限等离子体频率。这将是迈向光电器件的第一步。

This project aims to achieve a detailed understanding of the low-energy electronic structure of graphene based materials prepared by different methods such as epitaxial growth, CVD, exfoliation or decoupled graphene from bulk graphite. This will be done by magneto-optical studies in the THz- and sub-THz region using infrared and high frequency electron paramagnetic resonance spectrometers, respectively, both in frequency and magnetic field domains. We propose the first systematic comparative study of graphene specimens, which differ by substrate, defects, size and grain boundaries etc. Noninvasive low-energy (0.4-40 meV) experimental methods will bring decisive information about limits of intrinsic charge mobility, the electronic band structure (Fermi surface) and other phenomena, like confined plasmons, magnetic excitations etc. The low-energy excitations will be followed as a function of numbers of layers, to map and understand the change in electronic properties going from monolayer to bulk graphite. We will also perform the first microwave magneto-absorption measurements in gated graphene flakes with the aim to control confined plasmon frequency. This will be the first step towards optoelectronic devices.