We propose to entangle macroscopic atomic ensembles in cavity using EPR-correlated beams. We show how the field entanglement can be almost perfectly mapped onto the long-lived atomic spins associated with the ground states of the ensembles, and how it can be retrieved in the fields exiting the cavities after a variable storage time. Such a continuous variable quantum memory is of interest for manipulating entanglement in quantum networks.
@article{arxiv.quant-ph/0405020,
title = {Entanglement storage in atomic ensembles},
author = {Aurelien Dantan and Alberto Bramati and Michel Pinard},
journal= {arXiv preprint arXiv:quant-ph/0405020},
year = {2009}
}