Metamaterials have extraordinary abilities, such as imaging beyond the diffraction limit and invisibility. Many metamaterials are based on split-ring structures, however, like atomic orbital currents, it has long been believed that closed rings cannot produce negative refractive index. Here we report a low-loss and polarization-independent negative-index metamaterial made solely of closed metallic nanorings. Using symmetry breaking that negatively couples the discrete nanorings, we measured negative phase delay in our composite 'chess metamaterial'. The formation of an ultra-broad Fano-resonance-induced optical negativeindex band, spanning wavelengths from 1.3 to 2.3 mm, is experimentally observed in this structure. This discrete and mono-particle negative-index approach opens exciting avenues towards symmetry-controlled topological nanophotonics with on-demand linear and nonlinear responses.

We experimentally demonstrate linear bandgap guidance of optical vortices as high-gap defect modes (DMs) in twodimensional induced photonic lattices. We show that donut-shaped vortex beams can be guided in a tunable negative (lower-index) defect, provided that the defect strength is set at an appropriate level. Such vortex DMs have fine features in the "tails" associated with the lattice anisotropy and can be considered as a superposition of dipole DMs. Our numerical results find good agreement with experimental observations.

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