Entanglement of two atomic ensembles in coupled cavities via adiabatic passage

We propose a potentially practical scheme for creating entanglement between two atomic ensembles in two coupled cavities via adiabatic passage. The three-level Λ-type atoms in each ensemble dispersively interact with the nonresonant classical field and cavity mode. By choosing appropriate parameters of the system, the effective Hamiltonian describes two atomic ensembles interact with “the same cavity mode” and has a dark state. Consequently, the entanglement between the two ensembles is gained via adiabatic passage. Numerical calculations show that the scheme is robust against moderate fluctuations of the experimental parameters. In addition, the effect of decoherence can be suppressed effectively.