@article{35dea07058ba472f8df69c2a6dae7ea4,
title = "Observation of Quadratic (Charge-2) Weyl Point Splitting in Near-Infrared Photonic Crystals",
abstract = "Weyl points are point degeneracies that occur in momentum space of 3D periodic materials and are associated with a quantized topological charge. Here, the splitting of a quadratic (charge-2) Weyl point into two linear (charge-1) Weyl points in a 3D micro-printed photonic crystal is observed experimentally via Fourier-transform infrared spectroscopy. Using a theoretical analysis rooted in symmetry arguments, it is shown that this splitting occurs along high-symmetry directions in the Brillouin zone. This micro-scale observation and control of Weyl points is important for realizing robust topological devices in the near-infrared.",
author = "Christina J{\"o}rg and Sachin Vaidya and Jiho Noh and Alexander Cerjan and Shyam Augustine and {von Freymann}, Georg and Rechtsman, {Mikael C.}",
note = "Funding Information: C.J. and S.V. contributed equally to this work. C.J. gratefully acknowledges funding from the Alexander von Humboldt Foundation within the Feodor‐Lynen Fellowship program. G.v.F. acknowledges funding by the Deutsche Forschungsgemeinschaft through CRC/Transregio 185 OSCAR (project No. 277625399). The authors would like thank the Nano Structuring Center Kaiserslautern for technical support. M.C.R., S.V., J.N., and A.C. acknowledge the support of the U.S. Office of Naval Research (ONR) Multidisciplinary University Research Initiative (MURI) under Grant No. N00014‐20‐1‐2325. A.C. acknowledges support from the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science, and the Laboratory Directed Research and Development program at Sandia National Laboratories. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE's National Nuclear Security Administration under contract DE‐NA‐0003525. The views expressed in the article do not necessarily represent the views of the U.S. DOE or the United States Government. Publisher Copyright: {\textcopyright} 2021 The Authors. Laser & Photonics Reviews published by Wiley-VCH GmbH",
year = "2021",
doi = "10.1002/lpor.202100452",
language = "English (US)",
journal = "Laser and Photonics Reviews",
issn = "1863-8880",
publisher = "Wiley-VCH Verlag",
}