Antibunched N-photon bundles from dark states assisted by ac Stark shift

In this paper, we propose an interesting scheme to generate antibunched N -photon bundles from dark states by using a single-atom cavity quantum electrodynamics system. The dispersive coupling between the atom and cavity introduces a Stark shift to one of the ground states, while the resonant coupling, along with a control field, forms a coherent N -excitation dark state assisted by the shift. Consequently, super-Rabi oscillation is established between the vacuum state and the N -excitation dark state when a probe field weakly couples to two ground states, enabling antibunched N -photon bundle emission within long-lived atomic coherence. As a byproduct, the generated high-efficiency single-photon source with a large mean photon number and high fidelity is of great value in quantum information processing.