Long-distance atom-photon entanglement

Atoms and photons are well-suited candidates for quantum information processing and quantum communication. While atoms can be used for storage and manipulation, photons are ideal carriers for the transfer of quantum information. Our group pursues the goal of creating a basic node of a quantum communication network by entangling two independently trapped
⁸⁷
Rb atoms over a large distance. Besides its prospects in quantum communication (e.g. quantum repeater), this would also allow a loophole-free test of Bell's inequality which can help to conclusively answer the long-standing question about the completeness of the quantum theory. The key ingredient is atom-photon entanglement which will enable us to entangle two atoms by entanglement swapping. We plan to achieve a distance of 300m between two independent single atom traps.