Sachin Vaidya, Jiho Noh, Alexander Cerjan, Christina Jörg, Georg von Freymann, and Mikael C Rechtsman:
Phys. Rev. Lett., 125, 253902 (2020)
🔓 arXiv:2002.03215 (2020)
VWeyl 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.