Experimental realization of photonic topological insulator in a uniaxial metacrystal waveguide

Understand

Achieving robust transport has attracted much attention in both electronic and photonic systems.

• Time-reversal invariant photonic crystal can be employed to realize backscattering-immune chiral state, but the chiral bandgap is topologically trivial.
• Here, we designed and fabricated a metacrystal comprising non-resonant meta-atoms sandwiched between two metallic plates and the system exhibits topological phase transition as established by group classification.
• The nontrivial bandgap was confirmed by experimentally measured transmission spectra, calculated nonzero spin Chern number and Z2 index.