We investigate features of the surface plasmon polaritons (SPPs) hosted by a slot waveguide comprised of a Weyl semimetal in Voigt/Faraday configuration and a Dirac semimetal connected via a dielectric layer. In the Voigt configuration, SPP dispersion is nonreciprocal possessing unidirectional SPP modes in a wide range of frequency. However, the reciprocal SPP dispersion of the Faraday configuration composes of two distinct dispersion bands existing below or above the bulk plasmon frequency depending on the selection of the materials realizing Weyl and Dirac semimetal phases. We explain that these SPP modes are tunable with the thickness of the dielectric layer, the chemical potentials of the semimetals and the separation of the Weyl nodes in the Weyl semimetal. These structures provide a high level of functionality and tunability and may be employed in optical devices based on the unidirectional SPPs.

我们研究了表面等离子体激元 (SPP) 的特征，该槽波导由 Voigt/Faraday 配置的 Weyl 半金属和通过介电层连接的 Dirac 半金属组成。在 Voigt 配置中，SPP 色散是非互易的，在很宽的频率范围内具有单向 SPP 模式。然而，法拉第配置的互易 SPP 色散由两个不同的色散带组成，这些色散带存在于体等离子体频率之下或之上，具体取决于实现 Weyl 和 Dirac 半金属相的材料的选择。我们解释说，这些 SPP 模式可根据介电层的厚度、半金属的化学势和外尔半金属中外尔节点的分离进行调节。