Dark-state entanglement of two atomic ensembles via cavity superradiance
Kang Shen, Xiangming Hu, Fei Wang · Physical Review A · 2025
We propose an effective model leveraging cavity superradiance to achieve entanglement between two spatially separated two-level atomic ensembles trapped in a standing-wave optical cavity. This model is based on permutational symmetry breaking, which leads to the emergence of entangled quantum dark states with nonzero excitations but vanishing decay rate. This steady-state entanglement is created by purely dissipative dynamics, unlike the superradiance of permutationally symmetric two-level atoms, whose steady state is the ground state. Furthermore, we show that the entanglement is significantly enhanced near critical points in the superradiance potential because of the extremely high two-mode squeezing factor between two atomic ensembles. We also discuss spin squeezing in each atomic ensemble in the vicinity of specific critical points in the potential. These findings may play an important role in the generation of correlations immune to dissipation in separated atomic modes.