Entanglement concentration for two atomic ensembles using an effective atom-light beamsplitter

Deterministically Entangling Two Remote Atomic Ensembles via Light-Atom Mixed Entanglement Swapping

Entanglement of two distant macroscopic objects is a key element for implementing large-scale quantum networks consisting of quantum channels and quantum nodes. Entanglement swapping can entangle two spatially separated quantum systems without direct interaction. Here we propose a scheme of deterministically entangling two remote atomic ensembles via continuous-variable entanglement swapping be...

Nonsymmetric entanglement of atomic ensembles.

The entanglement of multiatom quantum states is considered. In order to cancel noise due to inhomogeneous light-atom coupling, the concept of matched multiatom observables is proposed. As a means to eliminate an important form of decoherence this idea should be of broad relevance for quantum information processing with atomic ensembles. The general approach is illustrated on the example of rota...

Entanglement storage in atomic ensembles

– We propose to entangle macroscopic atomic ensembles in cavity using EPRcorrelated 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 ...

2. Atom-light entanglement..........................................................................................3

Interference of Spontaneous Emission of Light from Two Atomic Ensembles

We demonstrate interference of spontaneous emission of light from two distant solid-state atomic ensembles, when both ensembles are coherently excited by a common laser source. Owing to a strong collective enhancement of the spontaneous emission, the atoms behave as ideal two-level quantum systems and no which-path information is left in the atomic ensembles after emission of a photon. This all...