Spectrally Robust Photon-Pair Generation in Topological Waveguide Arrays
The study compared homogeneous, trivial, and topological Su–Schrieffer–Heeger arrays to see which configuration protected spontaneous parametric down-conversion (SPDC) resonance spectra against disorder in tunnel couplings. Only the topological array maintained a stable resonance spectrum with fluctuations reduced by more than one order of magnitude, proving topology offers robust platforms for quantum information processing.