In-Plane Anisotropic Plasmons in Van Der Waals Thin Films of WTe2

IEEE Photonics Journal

Shaopeng Li¹  Qibing Sun² 

[1] Department of Physics, Shaanxi University of Science and Technology, Xi&x0027;an, China;

关键词: Plasmon;    anisotropy;    topological transition;   

DOI  :  10.1109/JPHOT.2022.3146208

来源: DOAJ

【 摘 要 】

Anisotropic plasmonic surface supports elliptic, hyperbolic and even flattened polaritons, which is quite interesting for the diffractionless and highly collimated propagation of infrared light at the nanoscale. However, direct real-space near-field observation of anisotropic plasmons as well as frequency dependent topological transitions in natural materials have not been realized. In this paper, we theoretically investigate real-space anisotropic plasmons in WTe₂ thin films by using a phenomenological cavity model, anisotropic near-field plasmonic images with specific interference patterns and isofrequency curves in momentum space have been demonstrated. Due to the frequency selective forbidden of plasmons along b axis, a topological transition from the elliptic to the hyperbolic regime is manifested. Moreover, the plasmons as well as topological transition present significant electrostatic-gating tunability. Our studies provide new insights into WTe₂ based plasmonic components for the manipulation of plasmon propagation, which capable of tailoring anisotropic two-dimensional light confinement in the far-infrared regime and can be applied to investigate other anisotropic materials.

【 授权许可】

Unknown