Nonequilibrium quantum states emerging from flippable spins in random networks

arXiv:2505.11466v2 Announce Type: replace Abstract: Recent advances in programmable quantum simulators have enabled the realization of irregular interaction networks, which natural crystal lattices cannot provide, together with time-resolved observation of quantum many-body dynamics. Understanding the nonequilibrium states that emerge from such networks has only just begun, and whether quantum many-body scar states can emerge in them remains open. Here, focusing on a quantum Ising spin system with random interaction networks under a weak transverse field, we introduce the flippability, the fraction of flippable spins, and present phenomenological laws that predict the emergence of quantum many-body scar states from the network structure. As the flippability increases, the Hilbert space becomes less fragmented. The largest kinetically accessible subspace shows nonintegrable level statistics, yet hosts a few eigenstates with abnormally low participation entropy, signalling scar states. Real-time dynamics from Fock states confirm these signatures: systems with higher flippability tend toward thermalization, whereas a few initial states show anomalously nonthermal dynamics. The flippability thus links the interaction-network structure of the Hamiltonian to nonequilibrium many-body dynamics without translational invariance, and may apply to other kinetically constrained quantum systems.