Nanooptics in 2D materials

by Pablo Alonso González (University of Oviedo)

Friday 3 May 2024, 11:00 → 13:00 Europe/Rome

Sala Lauree González GonzálezGonzálezG (Dip. di Fisica - Edificio G. Marconi)

Highly anisotropic crystals have recently attracted considerable attention due to their ability to support polaritons with unique properties, such as hyperbolic dispersion, negative phase velocity, or extreme confinement. In particular, the biaxial van der Waals semiconductor α-phase molybdenum trioxide (α-MoO3) has received much attention [1] due to its ability to support in-plane hyperbolic phonon polaritons (PhPs) —infrared (IR) light coupled to lattice vibrations in polar materials— with ultra-low losses, offering an unprecedented platform for controlling the flow of energy at the nanoscale. In this talk, we will show experimental demonstrations of the unique behavior of PhPs in these crystals, including the visualization of anomalous cases of the fundamental optical phenomena of refraction [2] and reflection [3], and the exotic phenomenon of canalization, in which PhPs propagate along a single direction with ultralow losses [4].

References: [1] W. Ma et al., Nature, 562, 557 (2018). [2] J. Duan et al., Nature Communications, 12, 1, 1-8 (2021). [3] G. Álvarez-Pérez et al., Science Advances 8, 29, (2022) [4] J. Duan et al., Nature Materials, 22, 867-872 (2023).