Multipartite entanglement generation and fidelity decay in disordered qubit systems

We investigate multipartite entanglement dynamics in disordered spin-1/2 lattice models exhibiting a transition from integrability to quantum chaos. Borrowing from the recently introduced generalized entanglement framework, we construct measures for correlations relative to arbitrary local and bi-local spin observables, and show how they naturally signal the crossover between distinct dynamical regimes. In particular, we find that the generation of global entanglement is directly ruled by the local density of states in the short time limit, whereas the asymptotic amount of entanglement is proportional to the degree of delocalization of the chaotic many-body state. Our results are relevant to the stability of quantum information in disordered quantum computing hardware.