Entanglement Purification with Hybrid Systems

We propose a scheme for continuous variable entanglement purification using the interaction of two-mode squeezed beams with cold trapped atomic ensembles. In the limit of very large number of atoms, a collective atomic ensemble excitation becomes a continuous quantity. Measurement of populations in the two lower levels is of non-Gaussian nature that is necessary for the entanglement purification. We foresee the use of this scheme for implementation of a continuous variable quantum repeater.