Group Velocity Modulation and Light Field Focusing of the Edge States in Chirped Valley Graphene Plasmonic Metamaterials
Author(s): Zhuo, Liqiang; He, Huiru; Huang, Ruimin; Su, Shaojian; Lin, Zhili; Qiu, Weibin; Huang, Beiju; Kan, Qiang
Source: NANOMATERIALS Volume: 11 Issue: 7 Article Number: 1808 DOI: 10.3390/nano11071808 Published: JUL 2021
Abstract: The valley degree of freedom, like the spin degree of freedom in spintronics, is regarded as a new information carrier, promoting the emerging valley photonics. Although there exist topologically protected valley edge states which are immune to optical backscattering caused by defects and sharp edges at the inverse valley Hall phase interfaces composed of ordinary optical dielectric materials, the dispersion and the frequency range of the edge states cannot be tuned once the geometrical parameters of the materials are determined. In this paper, we propose a chirped valley graphene plasmonic metamaterial waveguide composed of the valley graphene plasmonic metamaterials (VGPMs) with regularly varying chemical potentials while keeping the geometrical parameters constant. Due to the excellent tunability of graphene, the proposed waveguide supports group velocity modulation and zero group velocity of the edge states, where the light field of different frequencies focuses at different specific locations. The proposed structures may find significant applications in the fields of slow light, micro-nano-optics, topological plasmonics, and on-chip light manipulation.
Accession Number: WOS:000676274700001
eISSN: 2079-4991
Full Text: https://www.mdpi.com/2079-4991/11/7/1808