Mixed eigenstates in spin-boson systems with one-photon and two-photon interactions
This work investigates mixed eigenstates in spin-boson systems by comparing one-photon and two-photon interactions using a new generalized phase-space overlap index. The study shows that while both systems follow universal semiclassical condensation, the two-photon system exhibits different behavior regarding the fraction of mixed states. The research provides a clearer method to distinguish genuine mixed eigenstates.