Crafting the dynamical structure of synchronization by harnessing bosonic multilevel cavity QED

Many-body cavity QED experiments are established platforms to tailor and control the collective responses of ensembles of atoms, interacting through one or more common photonic modes. The rich diversity of dynamical phases they can host calls for a unified framework. Here we commence this program by showing that a cavity QED simulator assembled from N-level bosonic atoms can reproduce and extend the possible dynamical responses of collective observables occurring after a quench. Specifically, by initializing the atoms in classical or quantum states, or by leveraging intralevels quantum correlations, we craft on demand the entire synchronization/desynchronization dynamical crossover of an exchange model for SU(N) spins. We quantitatively predict the onset of different dynamical responses by combining the Liouville-Arnold theorem on classical integrability with an ansatz for reducing the collective evolution to an effective few-body dynamics. Among them, we discover a synchronized chaotic phase induced by quantum correlations and associated to a first-order nonequilibrium transition in the Lyapunov exponent of collective atomic dynamics. Our outreach includes extensions to other spin-exchange quantum simulators and a universal conjecture for the dynamical reduction of nonintegrable all-to-all interacting systems.