Ideal Photonic Weyl Nodes Stabilized by Screw Rotation Symmetry in Space Group 19

• Main Authors: Wenlong Gao, Yao-Ting Wang
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Crystals
• Subjects: Weyl nodes; screw rotation symmetry; line node; space group 19; space group 61
• Online Access: https://www.mdpi.com/2073-4352/10/7/605

Topological photonics have developed in recent years since the seminal discoveries of topological insulators in condensed matter physics for electrons. Among the numerous studies, photonic Weyl nodes have been studied very recently due to their intriguing surface Fermi arcs, Chiral zero modes and scattering properties. In this article, we propose a new design of an ideal photonic Weyl node metacrystal, meaning no excessive states are present at the Weyl nodes’ frequency. The Weyl node is stabilized by the screw rotation symmetry of space group 19. Group theory analysis is utilized to reveal how the Weyl nodes are spawned from line nodes in a higher symmetry metacrystal of space group 61. The minimum four Weyl nodes’ complex for time reversal invariant systems is found, which is a realistic photonic Weyl node metacrystal design compatible with standard printed circuit board techniques and is a complement to the few existing ideal photonic Weyl node designs and could be further utilized in studies of Weyl physics, for instance, Chiral zero modes and scatterings.