Possible realization of hyperbolic plasmons in a few-layered rhenium disulfide

TL;DR

This paper explores how few-layered rhenium disulfide can naturally support hyperbolic plasmons in the ultraviolet range due to its anisotropic dielectric properties, with tunability based on layer number.

Contribution

It demonstrates that ReS₂'s anisotropic dielectric function can host hyperbolic plasmons, a novel property for this material in the ultraviolet spectrum.

Findings

ReS₂ exhibits strong optical anisotropy.

Hyperbolic plasmons can occur in ReS₂ in the UV range.

Tuning layer number adjusts the plasmon frequency.

Abstract

The in-plane structural anisotropy in low-symmetric layered compound rhenium disulfide ($\text{ReS}_2$) makes it a candidate to host and tune electromagnetic phenomena specific for anisotropic media. In particular, optical anisotropy may lead to the appearance of hyperbolic plasmons, a highly desired property in optoelectronics. The necessary condition is a strong anisotropy of the principal components of the dielectric function, such that at some frequency range, one component is negative and the other is positive, i.e., one component is metallic, and the other one is dielectric. Here, we study the effect of anisotropy in $\text{ReS}_2$ and show that it can be a natural material to host hyperbolic plasmons in the ultraviolet frequency range. The operating frequency range of the hyperbolic plasmons can be tuned with the number of $\text{ReS}_2$ layers.