论文标题
石墨烯的光子和等离子过渡辐射
Photonic and plasmonic transition radiation from graphene
论文作者
论文摘要
在完整的Maxwell方程的框架中，我们系统地研究电磁辐射，即过渡辐射，当Swift电子垂直于单层石墨烯时。基于平面波的扩展和Sommerfeld的整合，我们证明了这种自由电子辐射过程在频域中的空间分布，这清楚地表明了光子和石墨烯等离子的宽带激发。此外，分析得出激发光子和石墨烯等离子的辐射光谱。我们发现光子和石墨烯等离子的激发有利于Swift电子的不同速度。具体而言，较高的电子速度可以引起光子以更好的方向性和较高强度的激发，而较低的电子速度可以在更广泛的频率范围内有效激发石墨烯等离子体。我们的工作表明，Swift带电颗粒与超薄2D材料或Metasurfaces之间的相互作用有望用于设计Terahertz On-Chip辐射源。
In the framework of full Maxwell equations, we systematically study the electromagnetic radiation, namely the transition radiation, when a swift electron perpendicularly crosses a monolayer graphene. Based on the plane wave expansion and the Sommerfeld integration, we demonstrate the spatial distribution of this free-electron radiation process in the frequency domain, which clearly shows the broadband excitation of both the photons and graphene plasmons. Moreover, the radiation spectra for the excited photons and graphene plasmons are analytically derived. We find that the excitation of photons and graphene plasmons favours different velocities of the swift electron. To be specific, a higher electron velocity can give rise to the excitation of photons with better directivity and higher intensity, while a lower electron velocity can enable the efficient excitation of graphene plasmons in a broader frequency range. Our work indicates that the interaction between swift charged particles and ultrathin 2D materials or metasurfaces is promising for the design of terahertz on-chip radiation sources.
