Vaidya Sachin, Noh Jiho, Cerjan Alexander, Jörg Christina, von Freymann Georg, Rechtsman Mikael C
Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Physics Department and Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
Phys Rev Lett. 2020 Dec 18;125(25):253902. doi: 10.1103/PhysRevLett.125.253902.
Weyl points are robust point degeneracies in the band structure of a periodic material, which act as monopoles of Berry curvature. They have been at the forefront of research in three-dimensional topological materials as they are associated with novel behavior both in the bulk and on the surface. Here, we present the experimental observation of a charge-2 photonic Weyl point in a low-index-contrast photonic crystal fabricated by two-photon polymerization. The reflection spectrum obtained via Fourier-transform infrared spectroscopy closely matches simulations and shows two bands with quadratic dispersion around a point degeneracy.
