TY - JOUR
T1 - Direct observation of topological surface-state arcs in photonic metamaterials
AU - Yang, Biao
AU - Guo, Qinghua
AU - Tremain, Ben
AU - Barr, Lauren E.
AU - Gao, Wenlong
AU - Liu, Hongchao
AU - Beri, Benjamin
AU - Xiang, Yuanjiang
AU - Fan, Dianyuan
AU - Hibbins, Alastair P.
AU - Zhang, Shuang
PY - 2017/7/21
Y1 - 2017/7/21
N2 - The discovery of topological phases has introduced new perspectives and platforms for various interesting physics originally investigated in quantum contexts and then, on an equal footing, in classic wave systems. As a characteristic feature, nontrivial Fermi arcs, connecting between topologically distinct Fermi surfaces, play vital roles in the classification 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 momentum space has been reported so far. Here, using near-field scanning measurements, we show the observation of photonic topological surface-state arcs connecting topologically distinct bulk states in a chiral hyperbolic metamaterial. To verify the topological nature of this system, we further observe backscattering-immune propagation of a nontrivial surface wave across a three-dimension physical step. Our results demonstrate a metamaterial approach towards topological photonics and offer a deeper understanding of topological phases in three-dimensional classical systems.
AB - The discovery of topological phases has introduced new perspectives and platforms for various interesting physics originally investigated in quantum contexts and then, on an equal footing, in classic wave systems. As a characteristic feature, nontrivial Fermi arcs, connecting between topologically distinct Fermi surfaces, play vital roles in the classification 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 momentum space has been reported so far. Here, using near-field scanning measurements, we show the observation of photonic topological surface-state arcs connecting topologically distinct bulk states in a chiral hyperbolic metamaterial. To verify the topological nature of this system, we further observe backscattering-immune propagation of a nontrivial surface wave across a three-dimension physical step. Our results demonstrate a metamaterial approach towards topological photonics and offer a deeper understanding of topological phases in three-dimensional classical systems.
KW - Metamaterials
KW - Microwave photonics
KW - Sub-wavelength optics
U2 - 10.1038/s41467-017-00134-1
DO - 10.1038/s41467-017-00134-1
M3 - Article
SN - 2041-1723
VL - 8
JO - Nature Communications
JF - Nature Communications
M1 - 97
ER -