The Rydberg blockade mechanism is a powerful tool for enabling deterministic entanglement in neutral-atom quantum computing and simulation. In this work, we investigate the coherent dynamics of a three-level atomic ensemble, where the highest energy level corresponds to a highly excited Rydberg state, and driven by two laser fields, incorporating detuning effects via an effective Hamiltonian that enforces the Rydberg blockade condition. First, we analyze the system’s eigen structure and derive conditions for the existence of a dark state. Then, to quantify entanglement generation, we compute the Fidelity with respect to a target Bell state and demonstrate that a gradient-free optimization of the single-atom detunings ∆ 1 and ∆ 2 can steer the system from the collective ground state into a high-Fidelity entangled superposition of excited and Rydberg levels. We validate this approach through time-domain simulations for both small ( N = 2 ) and mesoscopic ( N = 10 ) ensembles, achieving peak Bell-state fidelities exceeding 0.99 with appropriate detuning choices. Our results show that detuning control alone, without shaped pulses or adiabatic techniques, is sufficient to achieve fast and robust entanglement generation on experimentally relevant timescales. This strategy is scalable and relies solely on the spectral properties of the effective Hamiltonian, making it well-suited for extension to larger systems and more complex entangled targets.
