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arXiv · 2106.12119

Observation of Quadratic (Charge-2) Weyl Point Splitting in Near-Infrared Photonic Crystals

Christina Jörg·Sachin Vaidya·Jiho Noh·Alexander Cerjan·Shyam Augustine·Georg von Freymann·Mikael C. Rechtsman
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Abstract

Weyl points are point degeneracies that occur in momentum space of periodic materials, and are associated with a quantized topological charge. We experimentally observe in a 3D micro-printed photonic crystal that a charge-2 Weyl point can be split into two charge-1 Weyl points as the protecting symmetry of the original charge-2 Weyl point is broken. Moreover, we use a theoretical analysis to confirm where the charge-1 Weyl points move within the Brillouin zone as the strength of the symmetry breaking increases, and confirm it in experiments using Fourier-transform infrared spectrometry. This micro-scale observation and control of Weyl points is important for realizing robust topological devices in the near-infrared.

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Christina Jörg, Sachin Vaidya, Jiho Noh, Alexander Cerjan, Shyam Augustine, Georg von Freymann, Mikael C. Rechtsman. 2021-06-23. Observation of Quadratic (Charge-2) Weyl Point Splitting in Near-Infrared Photonic Crystals. https://doi.org/10.1002/lpor.202100452

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