Temperature-induced optical phase transitions in anisotropic WTe 2
Abstract
Tungsten ditelluride (WTe 2 ), a type-II Weyl semimetal, exhibits pronounced in-plane anisotropic permittivity, enabling highly tunable hyperbolic polaritons across a broad far-infrared frequency range. Here, we investigated the frequency- and temperature-dependent optical response of WTe 2 , focusing on its anisotropic permittivity and the resulting hyperbolic plasmon polariton dynamics. By combining infrared spectroscopy with analytical modeling and full-wave numerical simulations, we mapped the phase diagram within multiple Reststrahlen bands. By analyzing the evolution of its iso-frequency contours, we used the critical angle (Δθ), which defines the transition angle between hyperbolic (open) and elliptical (closed) regimes, to determine the propagation regimes in WTe 2 .
Fields of Study & Subjects
2D Materials and Applications
Advanced Thermoelectric Materials and Devices
Electronic and Structural Properties of Oxides
Publication details
- Journal / source
- Optical Materials Express
- Publisher
- Optica Publishing Group
- Volume
- 16
- Issue
- 8
- Pages
- 2590–2590
- Publication date
- 25 June 2026
- Language
- EN