Non-Abelian topological quantum light source

Abstract Non-Abelian topological charges herald a new epoch in topological classification, featuring multiple tangled-bandgaps that promise conceptual breakthroughs. Here, we engineered the first photonic non-Abelian topological insulators by the integrated waveguide and demonstrating a novel quantum light source that exhibits non-Abelian topological features. We experimentally observed the generation of a discrete-band two-photon source with extended wavelengths of signal and idler photons lying in S and L bands, respectively, exhibiting an enhanced coincidence-to-accidental ratio. Additionally, we demonstrated the robustness of this quantum light sources by introducing significant disorders. Such non-Abelian two-photon source can be engineered within the transmission window of the material as well as provides a natural scheme for optimizing the spectral purity towards robust indistinguishable photons. Our scheme paves the way for non-Abelian topological quantum device applications in quantum light sources engineering, quantum computing and quantum simulation as well as shedding light on interdisciplinary studies of non-Abelian physics and quantum optics.