Antihyperbolic surface waves with topological reconfiguration on twisted bilayer hyperbolic metasurfaces
Phys. Rev. B 114, 055408 – Published 10 July, 2026
DOI: https://doi.org/10.1103/s9j8-ky6c
Abstract
Twisted bilayer hyperbolic metasurfaces provide versatile control over surface-wave dispersion via rotational stacking, enabling highly directional canalization and flexible wave-front engineering. While prior studies have mainly focused on hyperbolic eigenmodes, the behavior of antihyperbolic surface waves—characterized by distinct polarization and substantially smaller wave vectors—remains largely unexplored. Here, we investigate antihyperbolic surface waves in twisted bilayer hyperbolic metasurfaces, revealing that their isofrequency contours undergo a topological reconfiguration from open to closed at a critical twist angle. Furthermore, we find that tuning the interlayer separation of bilayer metasurfaces can induce the conversion between anisotropic and isotropic surface-wave propagation. These findings demonstrate that antihyperbolic eigenmodes can offer a method for dispersion engineering in nanophotonics, paving the way for advanced wave-front control and topological photonic devices.
