Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf
1 PublikationControlling the Propagation Asymmetry of Hyperbolic Shear Polaritons in Beta-Gallium Oxide
Matson, J.; Wasserroth, S.; Ni, X.; Obst, M.; Diaz-Granados, K.; Carini, G.; Maria Renzi, E.; Galiffi, E.; Folland, T. G.; Eng, L. M.; Klopf, J. M.; Mastel, S.; Armster, S.; Gambin, V.; Wolf, M.; Kehr, S. C.; Alu, A.; Paarmann, A.; Caldwell, J. D.
Abstract
Structural anisotropy in crystals is crucial for controlling light propagation, particularly in the infrared spectral regime where optical frequencies overlap with crystalline lattice resonances, enabling light-matter coupled quasiparticles called phonon polaritons (PhPs). Exploring PhPs in anisotropic materials like hBN and MoO3 has led to advancements in light confinement and manipulation. In a recent study, PhPs in the monoclinic crystal β-Ga2O3 (bGO) were shown to exhibit strongly asymmetric propagation with a frequency dispersive optical axis. Here, using scanning near-field optical microscopy (s-SNOM), we directly image the symmetry-broken propagation of hyperbolic shear polaritons in bGO. Further, we demonstrate the control and enhancement of shear-induced propagation asymmetry by varying the incident laser orientation and polariton momentum using different sizes of nano-antennas. Finally, we observe significant rotation of the hyperbola axis by changing the frequency of incident light. Our findings lay the groundwork for the widespread utilization and implementation of polaritons in low-symmetry crystals.
Keywords: FEL; FELBE; s-SNOM; 2D Materials; THz; phonon polaritons; near-field; nanoscale
Beteiligte Forschungsanlagen
- Strahlungsquelle ELBE DOI: 10.17815/jlsrf-2-58
- F-ELBE
Verknüpfte Publikationen
- DOI: 10.17815/jlsrf-2-58 is cited by this (Id 37379) publication
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Nature Communications 14(2023), 5240
DOI: 10.1038/s41467-023-40789-7
Cited 10 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-37379