We propose a scheme that the material dispersion can be immune in a kind of photonic topological metacrystal with uniform permittivity and permeability but staggered bianisotropy. The topological behaviors can be maintained even though the metamaterials are intrinsically dispersive. A nontrivial topological band gap with a large gap spin Chern number is confirmed in such dispersion-immune photonic topological metacrystals. Two proposals of a robust pseudospin-polarized power splitter and a slow-light waveguide show evidence on the manipulation of the pseudospin-momentum locked states in a backscattering-free manner. In addition, a realistic design of a nontrivial dispersion-immune photonic metacrystal is also issued and discussed.

• Received 18 March 2015
• Revised 5 July 2015

DOI:https://doi.org/10.1103/PhysRevB.92.014210