2017/09/18 by Biao Yang, Yang, Biao, Qinghua Guo +25
Materials Science · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Metamaterials and Metasurfaces Applications #Optics (physics.optics) #Quantum Mechanics and Non-Hermitian Physics #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.1709.06065
openalex publication_date 2017/09/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Weyl points, serving as monopoles in the momentum space and laying the foundation of topological gapless phases, have recently been experimentally demonstrated in various physical systems. However, none of the observed Weyl degeneracies are ideal: they either offset in energy or coexist with trivial dispersions at other momenta. The lack of an ideal Weyl system sets a serious limit to the further development of Weyl physics and potential applications. Here, by constructing a photonic metamaterial, we experimentally observe an ideal Weyl system, whose nodal frequencies are pinned by symmetries to exactly the same value. Benefitting from the ideal Weyl nodes, we are able to map out the complete evolution of the helicoid surface states spinning around the projections of each Weyl nodes. Our discovery provides an ideal photonic platform for Weyl systems and novel topological devices.