We propose a photonic crystal with Z2 topology purely based on dielectric materials. Deforming the honeycomb lattice of dielectric cylinders, such as silicon, we identify a pseudo spin degree of freedom, and the associated time-reversal symmetry similar to that of electronic systems [1]. We demonstrate theoretically the nontrivial topology by showing photonic band inversion, and helical edge electromagnetic-wave propagation. Without requiring gyromagnetic, bi-anisotropic or piezo-magnetic materials, this topological photonic crystal can be fabricated easily and is compatible to electronics.
Reference:
[1] L.-H. Wu and X. Hu: Phys. Rev. Lett. vol. 114, 223901 (2015).
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