Free-fermion spectral structure enables strange nonchaotic attractor classification in Aubry-Andre-Harper quantum reservoirs
An Aubry-Andr\'{e}-Harper (AAH) quantum reservoir classifies strange nonchaotic attractors (SNAs) against chaos, substantially outperforming reservoirs built from dense random matrices on the full Fock space. Ablations and controlled interventions identify \emph{free-fermion one-body transition sparsity}, rather than p...