Unidirectional transport in amorphous topological photonic crystals

Many works on topological insulators have focused on periodic lattice systems; where short- and long-range order is considered. Here we construct a two-dimensional amorphous photonic crystal with short-range order and a controllable level of long-range order and experimentally investigate the transport of topological edge states in this amorphous system. We demonstrate that topology properties remain constant with unidirectional edge state propagation; immune to specific disorder strength. The partition phenomena of edge states are also observed at the intersection of four topological channels in microwave experiments. This proposed amorphous configuration provides new opportunities to explore the relationship between short-range order and topology and may alleviate the fabrication difficulties of topological optical devices for practical applications.