Opt Lett. 2018 Dec 1;43(23):5737-5740. doi: 10.1364/OL.43.005737.
Recent progress on anisotropic 2D materials brings new technologies for directional guidance of hyperbolic plasmons. Here, we investigate the plasmonic modes in twisted bilayer 2D materials (e.g., black phosphorous). Calculated dispersion curves show that two hyperbolas split as the twisted angle increases. The topological transition from closed ellipses to open hyperbolas is achieved by varying the frequency, indicating switching between highly directional and omnidirectional plasmons. These findings will provide potential applications of anisotropic 2D materials in the design of tunable field effect transistors and waveguides.
二维各向异性材料的最新进展为双曲等离子体的定向引导带来了新的技术。在这里，我们研究了扭曲双层二维材料（如黑磷）中的等离子体模式。计算得到的色散曲线表明，随着扭曲角度的增加，两个双曲线会分开。通过改变频率，可以实现从封闭椭圆到开放双曲线的拓扑转变，这表明在高度定向和各向同性等离子体之间进行切换。这些发现将为各向异性二维材料在可调谐场效应晶体管和波导的设计中提供潜在的应用。
