Polariton canalization in hyperbolic metasurfaces composed of van der Waals quaternary oxide MgTeMoO₆

Expanding the library of van der Waals (vdW) materials with exceptional optical anisotropy and strong subwavelength confinement can broaden photonic applications beyond the established hBN and α-MoO₃ platforms. Recently, orthorhombic quaternary oxide MgTeMoO₆ has emerged as a promising candidate, offering tunable polaritonic responses and unique topological dispersion characteristics. Here, we numerically study polariton canalization in a metasurface composed of MgTeMoO₆ nanoribbons in the mid-infrared regime. This metasurface induces synthetic transverse optical resonances, facilitating ultra-narrow canalized polariton propagation with beam widths around 210 nm (approximately λ₀/50, where λ₀ is the free-space wavelength). Notably, these canalized polaritons exhibit exceptionally slow group velocities (< 4.0 × 10⁻4c) and long lifetimes (~5 ps), outperforming established vdW platforms such as hBN and α-MoO₃. Comprehensive parametric analyses reveal how geometric dimensions and substrates impact canalization characteristics, elucidating the underlying physical mechanisms. Moreover, simulated experimental conditions validate the practical feasibility of the proposed design. Our findings demonstrate significant potential of the metasurface of vdW quaternary oxides, paving the way for polaritonic applications in integrated photonics and super-resolution imaging.