Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Final Activity Report Summary - EMALI (Engineering, Manipulation and Characterization of Quantum States of Matter and Light)

Quantum state engineering is the art of controlling the properties of basic quantum objects, such as atoms, molecules, photons or more complex quantum systems such as electrons confined in quantum dots on surfaces, or optical cavities hosting a controlled number of photons and coupled to other quantum objects. Quantum state engineering allows the control of properties of such quantum systems. These objects are crucial ones in modern or future inherently secure communication systems, which are beginning to hit the market. A main objective of the EMALI network was - along with the related training of fellows - to further develop the art of quantum state engineering, already highly developed for atoms and photons and to carry the schemes over to more complex systems and thus bringing the tools closer to application.

In that spirit a pool of novel approaches, theoretical and experimental, has been developed within the network and through close collaboration between partner groups. As an example, new schemes for high capacity quantum memories, an essential component in any quantum communication system, have been developed and successfully demonstrated. New schemes for deterministic photon sources, which will send out just one photon on demand, have been implemented along with novel experimental schemes to confine atoms to arbitrarily shaped arrays of traps formed by light. In such arrangements each one of the many traps carries just one atom, which can be individually addressed and manipulated.

Along a different line of projects, quantum state engineering with atomic ensembles has been lifted to qualitatively new level by significantly adding to the toolbox for quantum operations on combined light-matter states to enable storage and engineering in many-particles systems. Furthermore, the art of trapping ions and of controlling their mutual position on the nano-scale has been significantly advanced by using new concepts from control theory. Many more examples of this type relate to the control of electrons in quantum dots or other quantum systems in solid state environment. The use of multi-photon states in quantum communication systems has been pioneered as well.

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