Observation of naturally canalized phonon polaritons in LiV2O5 thin layers

Autor: Ana I. F. Tresguerres-Mata, Christian Lanza, Javier Taboada-Gutiérrez, Joseph. R. Matson, Gonzalo Álvarez-Pérez, Masahiko Isobe, Aitana Tarazaga Martín-Luengo, Jiahua Duan, Stefan Partel, María Vélez, Javier Martín-Sánchez, Alexey Y. Nikitin, Joshua D. Caldwell, Pablo Alonso-González
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Nature Communications, Vol 15, Iss 1, Pp 1-10 (2024)
Druh dokumentu: article
ISSN: 2041-1723
DOI: 10.1038/s41467-024-46935-z
Popis: Abstract Polariton canalization is characterized by intrinsic collimation of energy flow along a single crystalline axis. This optical phenomenon has been experimentally demonstrated at the nanoscale by stacking and twisting van der Waals (vdW) layers of α-MoO3, by combining α-MoO3 and graphene, or by fabricating an h-BN metasurface. However, these material platforms have significant drawbacks, such as complex fabrication and high optical losses in the case of metasurfaces. Ideally, it would be possible to canalize polaritons “naturally” in a single pristine layer. Here, we theoretically predict and experimentally demonstrate naturally canalized phonon polaritons (PhPs) in a single thin layer of the vdW crystal LiV2O5. In addition to canalization, PhPs in LiV2O5 exhibit strong field confinement ( $${{{{{{\boldsymbol{\lambda }}}}}}}_{{{{{{\bf{p}}}}}}} \sim \frac{{{{{{{\boldsymbol{\lambda }}}}}}}_{{{{{{\bf{0}}}}}}}}{{{{{{\bf{27}}}}}}}$$ λ p ~ λ 0 27 ), slow group velocity (0.0015c), and ultra-low losses (lifetimes of 2 ps). Our findings are promising for the implementation of low-loss optical nanodevices where strongly directional light propagation is needed, such as waveguides or optical routers.
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