Anderson transition in a non-Hermitian cavity-magnonic topological chain

Anderson transition, describing the disorder-driven change from extended quantum states to localized ones, plays a fundamental role in understanding wave transport in disordered systems. Here, we realize Anderson transition in a cascaded cavity-magnon system by mapping it to an effective Su-Schrieffer-Heeger model. Within this framework, on-site magnonic disorder is partially transferred—via linear cavity-magnon coupling—to cavity-dominated polaritons, introducing what we term “pseudo-disorder” into the topological chain. Beyond verifying bulk-boundary correspondence in both Hermitian and non-Hermitian regimes, we identify Anderson localization through Poisson-distributed level-spacing statistics. Moreover, under non-Hermitian conditions, we observe that non-Bloch PT -symmetry-like breaking triggers a transition from real-energy to complex-energy localized modes. This work deepens the understanding of disorder-induced localization in non-Hermitian topological systems and reveals the spectral signatures of the Anderson transition beyond the Hermitian paradigm.