Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)
Remote entanglement between a single atom and a Bose-Einstein condensate
Carolin Hahn, Matthias Lettner, Martin Mücke, Stefan Riedl, Christoph Vo, Simon Baur, Jörg Bochmann, Stephan Ritter, Stephan Dürr, Gerhard Rempe
Abstract
Entanglement has been recognised as a puzzling yet central element of quantum physics. While photons serve as flying qubits to distribute entanglement, the entanglement of stationary qubits at remote sites is a key resource for envisioned applications like distributed quantum computing. In our experiment we create remote entanglement between a single atom located inside a high-finesse optical cavity and a Bose-Einstein condensate (BEC). To this end we generate a single photon in the atom-cavity system, entangling the photon polarisation with the atomic Zeeman state. The photon is transported to a different laboratory in an optical fiber, where it is stored in a BEC employing electromagnetically induced transparency (EIT). This converts the atom-photon entanglement into remote matter-matter entanglement. Subsequently we map the matter-matter entanglement onto photon-photon entanglement. The experimental setup is sketched in Fig. 1.