Spin and orbital angular momenta of light are important degrees of freedom in nanophotonics which control light propagation, optical forces, and information encoding. Here, it is shown that graphene‐supported plasmonic nanostructures with broken rotational symmetry provide a surprising spin to orbital angular momentum conversion, which can be continuously controlled by changing the electrochemical potential of graphene. Upon resonant illumination by a circularly polarized plane wave, a polygonal array of indium‐tin‐oxide nanoparticles on a graphene sheet generates the scattered field carrying electrically‐tunable orbital angular momentum. This unique photonic spin‐orbit interaction occurs due to the strong coupling between graphene plasmon polaritons and localized surface plasmons of the nanoparticles and leads to the controlled directional excitation of graphene plasmons. The tuneable spin‐orbit conversion paves the way for high‐rate information encoding in optical communications, electric steering functionalities in optical tweezers, and nanorouting of higher‐dimensional entangled photon states.

中文翻译：

---

具有破碎的旋转对称性的石墨烯基纳米结构中自旋轨道耦合的电控制

光的自旋和轨道角动量是控制光传播，光学力和信息编码的纳米光子学中的重要自由度。此处显示，具有破碎的旋转对称性的石墨烯支撑的等离激元纳米结构提供了令人惊讶的自旋至轨道角动量转换，可以通过改变石墨烯的电化学势来对其进行连续控制。在圆偏振平面波的共振照明下，石墨烯片上的氧化铟锡纳米粒子的多边形阵列会产生带有电可调轨道角动量的散射场。这种独特的光子自旋轨道相互作用是由于石墨烯等离激元极化子与纳米粒子的局部表面等离激元之间的强耦合而发生的，并导致了石墨烯等离激元的受控定向激发。可调谐的自旋轨道转换为光通信中的高速率信息编码，光镊中的电动转向功能以及高维纠缠光子态的纳米路由铺平了道路。