2021/02/24 by Haedong Park, Stephan Wong, Xiao Zhang +1 · 31 citations
Physics and Astronomy · #Degeneracy (biology) #Dielectric #Eigenvalues and eigenvectors #NODAL #Photonic Crystals and Applications #Photonic crystal #Photonics #Position and momentum space #Quantum Mechanics and Non-Hermitian Physics #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.mes-hall #physics.optics
paper · pdf · open access · doi:10.1021/acsphotonics.1c00876
published in ACS Photonics 8(9), 2746-2754 (American Chemical Society) · 35 pages, 12 figures
arxiv created 2021/02/24 · openalex created_date 2021/03/01 · openalex publication_date 2021/08/30 · arxiv updated 2021/09/10 · openalex updated_date 2026/08/05
High Resolution Image Download MS PowerPoint Slide A nodal link is a special form of a line degeneracy (a nodal line) between adjacent bands in the momentum space of a three-dimensional topological crystal. Unlike nodal chains or knots, a nodal link consists of two or more mutually linked rings that do not touch each other. Recent studies on non-Abelian band topology revealed that the topological charges of the nodal links can have the properties of quaternions. However, a photonic crystal that has a nodal link with non-Abelian charges has not been reported. Here, we propose dielectric photonic crystals in the form of double diamond structures that realize the nodal links in the momentum space. By examining the evolution of the eigenstate correlations along closed loops that enclose the nodal line(s) of the links, their non-Abelian topological charges are also analyzed. The proposed design scheme and theoretical approach in this work will allow for experimental observation of photonic non-Abelian charges in purely dielectric materials and facilitate the control of the degeneracy in complex photonic structures.