论文标题
石墨烯PN连接中的梯度指数电子光学元件
Gradient-index electron optics in graphene pn junctions
论文作者
论文摘要
我们研究了光滑石墨烯PN连接中的电子传输，该连接是通过逐渐变化的静电电势产生的。数值计算出的相干流动模式可以在很大程度上以半古典轨迹来理解，这相当于在介质中获得的光束逐渐变化的折射率。在光滑的连接中，出现了能量禁止的区域，这些区域会增加反射并可以产生明显的干扰模式，例如，耳语画廊模式。研究的设备不仅证明了石墨烯PN连接（例如Luneburg和Maxwell镜头）中梯度索引电子光学元件的可行性，而且还可能具有技术应用，例如电子束分配器，焦点和波导。半古典轨迹提供了一种有效的工具，可以估算此类纳米电子设备中的当前流动路径。
We investigate the electron transport in smooth graphene pn junctions, generated by gradually varying electrostatic potentials. The numerically calculated coherent current flow patterns can be understood largely in terms of semi-classical trajectories, equivalent to the ones obtained for light beams in a medium with a gradually changing refractive index. In smooth junctions, energetically forbidden regions emerge, which increase reflections and can generate pronounced interference patterns, for example, whispering gallery modes. The investigated devices do not only demonstrate the feasibility of the gradient-index electron optics in graphene pn junctions, such as Luneburg and Maxwell lenses, but may have also technological applications, for example, as electron beam splitters, focusers and waveguides. The semi-classical trajectories offer an efficient tool to estimate the current flow paths in such nano-electronic devices.
