Realizing multiple-qubit entangling gate in Rydberg atoms via soft quantum control

Entangling gates are important for the generation of entanglement in quantum communicational and computational tasks. In this work, we propose an efficient protocol to realize the multi-qubit entangling gates with high fidelity in Rydberg atoms. Particularly, we apply the technique of soft quantum control to design the off-resonant pulses such that the atoms are driven to the ground-state subspace via unconventional Rydberg pumping. Thus, our scheme is insensitive to the decay effect as all atoms are only virtually excited. Moreover, Gaussian temporal modulation is further adopted to improve its robustness against the model uncertainty, such as operating time and environment noise. Finally, we perform numerical simulation to validate the effectiveness of our scheme. Hence, our work has potential applications in quantum information processing based on Rydberg atoms. Copyright (C) 2022 EPLA