ABSTRACT Bell state and W state are not just common entangled states, they are foundational resources in the field of quantum information. In this scheme, a Rydberg atomic ensemble with a four‐level “”‐shaped structure is confined within a Rydberg blockade sphere to form a superatom. Exploiting the unique advantages of the weak cavity field limit, the quantum information can be encoded with reliability on the superatom's effective energy levels. By integrating the methods of quantum Zeno dynamics (QZD) and Lewis‐Riesenfeld (LR) invariants, the Bell state, three‐qubit W state, and ‐qubit W state are prepared rapidly. Furthermore, the influences exerted by decoherence factors are also factored in. Numerical simulations confirm that the present scheme not only achieves high fidelities but also exhibits robustness against these decoherence factors. Finally, we further investigate the influences of parameter fluctuations on fidelities, and the results demonstrate that the fidelities of the proposed scheme remain robust against parameter fluctuations.
Liu et al. (Sun,) studied this question.