Entanglement storage in atomic ensembles

Laboratoire Kastler Brossel, Université Pierre et Marie Curie 4 place Jussieu, 75252 Paris Cedex 05, France

Received: 5 May 2004
Accepted: 19 July 2004

Abstract

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.