The topological features of optical vortices have been opening opportunities for free-space and on-chip photonic technologies, e.g., for multiplexed optical communications and robust information transport. In a parallel but disjoint effort, polar anisotropic van der Waals nanomaterials supporting hyperbolic phonon polaritons (HP²s) have been leveraged to drastically boost light-matter interactions. So far HP² studies have been mainly focusing on the control of their amplitude and scale features. Here we report the generation and observation of mid-infrared hyperbolic polariton vortices (HP²Vs) associated with reconfigurable topological charges. Spiral-shaped gold disks coated with a flake of hexagonal boron nitride are exploited to tailor spin–orbit interactions and realise deeply subwavelength HP²Vs. The complex interplay between excitation spin, spiral geometry and HP² dispersion enables robust reconfigurability of the associated topological charges. Our results reveal unique opportunities to extend the application of HP²s into topological photonics, quantum information processing by integrating these phenomena with single-photon emitters, robust on-chip optical applications, sensing and nanoparticle manipulation.

光学涡旋的拓扑特征为自由空间和片上光子技术提供了机会，例如，用于多路复用光通信和强大的信息传输。在一项并行但不相交的努力中，支持双曲声子极化激元（HP ² s）的极性各向异性范德华纳米材料已被用来大幅增强光与物质的相互作用。到目前为止，HP ^2的研究主要集中在其幅度和尺度特征的控制上。在这里，我们报告了与可重构拓扑电荷相关的中红外双曲极化激元涡旋（HP ² Vs）的产生和观察。利用涂有六方氮化硼薄片的螺旋形金盘来调整自旋轨道相互作用并实现深亚波长 HP ² Vs。激发自旋、螺旋几何结构和 HP ²色散之间复杂的相互作用使得相关拓扑电荷具有强大的可重构性。我们的研究结果揭示了将 HP ²的应用扩展到拓扑光子学、量子信息处理（通过将这些现象与单光子发射器集成）、强大的片上光学应用、传感和纳米粒子操纵的独特机会。