Direct observation of topological surface-state arcs in photonic metamaterials (dataset)

The article associated with this dataset is in ORE at http://hdl.handle.net/10871/28649The discovery of topological phases introduces new perspectives and platforms for various interesting physics originally investigated in quantum context and then, on an equal footing, in classic wave systems, such as photonics, acoustics and mechanics. As a characteristic feature, nontrivial Fermi arcs, connecting between topologically distinct Fermi surfaces, play vital roles in the clarification of Dirac and Weyl semimetals and have been observed in quantum materials very recently. However, in classical systems, no direct experimental observation of Fermi arcs in the momentum space has been reported so far. Here, using near-field scanning measurements, we show the observation of a photonic Fermi arcs connecting topologically distinct bulk states in chiral hyperbolic metamaterials. To verify the topological nature of this system, we further observe backscattering-immune propagation of nontrivial surface wave across a three-dimension physical step. Our results demonstrate metamaterial approach towards topological photonics and offer a deeper understanding of topological phases in three-dimension classical systems.This work was financially supported by ERC Consolidator Grant (Topological), the Royal Society and the Wolfson Foundation. B.Y. acknowledges China Scholarship Council (201306110041). S.Z. and B.B. acknowledge support from the Royal Society. Y.X. and D.F. acknowledge support from the National Natural Science Foundation of China (Grant Nos. 61490713 and 61505111). Q.G. acknowledges support from the National Natural Science Foundation of China (Grant No. 11604216). L.E.B., B.T. and A.P.H. acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1)