Recently, the discovery of topological photonic alloys with a local breakdown of time-reversal symmetry (TRS) has significantly broadened our understanding of conventional photonic Chern insulators with global TRS breaking and robust chiral edge states (CESs). However, to date, topological photonic alloys have been limited to periodic or quasiperiodic lattices, which have both long-range and short-range orders. It is still an open question whether the concept of topological photonic alloy can be extended to amorphous lattices that lack long-range order but only have short-range order. In this article, by mixing magnetized and nonmagnetized gyromagnetic rods in disordered lattices, we theoretically demonstrate that amorphous topological photonic alloys can support nontrivial Chern band gaps and robust CESs. Moreover, by increasing the disorder strength in amorphous lattices, we find that the threshold concentration of magnetized gyromagnetic rods to open the Chern band gaps also increases. Beyond a critical disorder strength, the signatures of Chern band gaps and CESs thoroughly disappear, even with pure magnetized gyromagnetic rods. Our work broadens the research scope of topological photonic alloys and may have potential applications in nonreciprocal topological photonic devices.

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• Chern insulators
• Topological materials
• Disordered alloys
• Photonic crystals