SKM 2023 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DS: Fachverband Dünne Schichten
DS 7: 2D Materials and their Heterostructures IV
DS 7.1: Vortrag
Dienstag, 28. März 2023, 11:15–11:30, SCH A 316
THz-Light Canalization by means of Phonon Polaritons in 2D van der Waals Materials — •Maximilian Obst1,2, Tobias Nörenberg1,2, Gonzalo Álvarez-Pèrez3, Thales V.A.G. de Oliveira4, Alexey Nikitin5, Pablo Alonso-González3, J. Michael Klopf4, Susanne C. Kehr1,2, and Lukas M. Eng1,2 — 1TU Dresden, Germany — 2Würzburg-Dresden Cluster of Excellence - EXC 2147 (ct.qmat), Germany — 3University of Oviedo, Spain — 4HZDR, Dresden, Germany — 5DIPC, Donostia-San Sebastian, Spain
Hyperbolic phonon polaritons (PhP) in anisotropic, 2D van der Waals materials present a promising platform to shrink THz optics into nm-sized volumes, as they enable ultra-high field confinement. Recently, controlled PhP dispersion tuneability was demonstrated at MIR wavelengths by vertically stacking two α-MoO3-flakes under a well-defined twist-angle θ, introducing a topological transition, where PhPs propagate along one distinct direction (so-called ’canalized propagation’)[1].
In this talk, we explore the THz dispersion tunability in twisted bilayer MoO3 at frequencies ranging from ν = 8.28 to 9.38 THz, for which the existence of hyperbolic PhP has been demonstrated recently [2], and where longer (THz) wavelengths make strong confinement even more desirable. We demonstrate the transition from hyperbolic to elliptic propagation of these PhPs by varying both θ and ν and report the very first observation of canalized PhPs in the THz spectral range, i.e., for ν = 8.67 THz and θ = 50∘.
[1] G. Hu et al., Nature 582, 209 (2020).
[2] T.V.A.G. de Oliveira et al., Adv. Mater. 33, 2005777 (2021).