**Controlling EPR and Bell correlations in Bose-Einstein condensates**

We bring together researchers on quantum information theory, Bose-Einstein condensates and atom interferometry to create, detect and exploit Einstein-Podolsky-Rosen and Bell entanglement in atomic Bose-Einstein condensates. These represent much stronger forms of entanglement than the non-classical correlations created so far and are largely unexplored.

Our purpose is both to gain a deeper understanding of quantum information in many body systems as well as to develop practical approaches for manipulating and exploiting it. The main targets are (i) to take advantage of this type of quantum correlation, (ii) to implement device-independent entanglement witnesses, (iii) to explore fundamental aspects of quantum mechanics, and (iv) to realize proof-of-principle implementations of quantum information and quantum measurement protocols with atomic many-body systems. Atomic interactions in BEC's constitute a non-linearity highly analogous to four-wave mixing or parametric down-conversion in optics, and hence can create strong entanglement. Two separate lines of research have been pursued in the past; on the one hand, one can use the spin degrees of freedom of an atom to produce atom pairs whose spins are entangled, and on the other hand one can entangle the motional degrees of freedom in a spirit close to that of the original EPR proposal. In the CEBBEC project, these two lines of research will be brought together in both the technological sense (using one kind of entanglement to make another) and conceptual one (for example studying complex situations in which both spin and motion are entangled) giving rise to new possibilities for applications and new theoretical challenges. The participating partners have developed sophisticated detection technologies, which allow us to make new types of measurements. We intend to respond to the great need for theoretical work to understand and exploit them. Finally, we will address practical applications and explore their metrological validity.

**CONSORTIUM**

**Coordinator: Christoph Westbrook (Insitut d’Optique Laboratoire Charles Fabry, FR)**- Carsten Klempt (Institut für Quantenoptik, Universität Hannover, DE)
- Marie Bonneau (Technische Universität Wien, AT)
- Géza Tóth (University of the Basque Country, ES)
- Augusto Smerzi (Consiglio Nazionale delle Ricerche, IT)