Separated atomic ensembles: Multimode squeezed states and multipartite entangled states

摘要

We show that, in analogy to light fields, effective bosonic modes of atomic ensembles in the Holstein-Primakoffnrepresentation can be prepared in multimode squeezed states, and multipartite continuous-variable cluster andnGreenberger-Horne-Zeilinger (GHZ) entangled states. Our scheme uses a cascade of optical cavities, in eachnof which one atomic ensemble is placed. Through Raman transitions between stable atomic ground states, thenatomic ensembles are in the interactions with the cavity and laser fields. Because of the long-lived ground states,nthe atomic ensembles act as quantum network nodes, whose cluster entangled states are applicable in the one-waynquantum computer, and whose GHZ entangled states have potential for quantum communication.