Strong nonreciprocal hyperbolic metamaterials mimicked by Weyl semimetal–dielectric multilayers
Phys. Rev. B 113, 125424 – Published 18 March, 2026
DOI: https://doi.org/10.1103/gwxd-nlfl
Abstract
Nonreciprocity has received much attention recently in the photonics community. However, nonreciprocal hyperbolicity has rarely been investigated in spite of its significance, and it has been limited to the perturbative regime in magneto-optical metamaterials. This work reports strong nonreciprocal hyperbolicity in a Weyl semimetal–dielectric multilayered metamaterial. The dispersion relations are analyzed in the nonperturbative regime, and their behaviors are investigated depending on structural and material parameters. Although the metamaterial consists of an intrinsically nonreciprocal Weyl semimetal, nonreciprocity can be obtained only when the Weyl semimetal layer is surrounded by dielectric layers with different refractive indices in the unit cell. The metamaterial slab exhibits hyperbolicity-induced negative refraction with significantly asymmetric transmittances and absorptances for forward and backward incidences, originating from nonreciprocal dissipation. In an idealized loss-free case, nevertheless, the structure does not show asymmetric transmission due to vanishing optical loss, leading to only an asymmetric phase of the transmission coefficient by nonreciprocal dispersion. Strong nonreciprocal hyperbolicity in Weyl semimetal–based multilayered metamaterials is of great significance from a fundamental point of view and has great value in practice as well due to the unnecessariness of applying an external field.
