Freiburg 2019 – wissenschaftliches Programm
FM 84.17: Poster
Donnerstag, 26. September 2019, 16:30–18:30, Tents
Towards long-time entanglement between a single optically trapped atom and a single photon — •Wei Zhang1, Tim van Leent1, Robert Garthoff1, Kai Redeker1, Matthias Seubert1, Wenjamin Rosenfeld1,2, and Harald Weinfurter1,2 — 1Fakultät für Physik, Ludwig-Maximilians-Universität, Munich, Germany — 2Planck- Institut für Quantenoptik, Garching, Germany
The most fundamental task for a quantum network is to generate atom-photon entanglement with long coherence time.
At present, for atom-photon states of a single optically trapped Rb-87 atom and its emitted photons, there are two decoherence mechanisms. One is motional decoherence in the dipole trap and the other is magnetic decoherence caused by the fluctuation of external magnetic fields. The proposed method is to use a standing-wave dipole trap to confine the atom in space thus reducing motional decoherence. At the same time, this optics can be used to apply stimulated Raman adiabatic passage to coherently transfer the entangled atomic state to the new atomic states which is 500 hundred times less-sensitive to magnetic-field fluctuations.
The coherence time for an atom-photon entangled state is expected to be increased by 2 orders of magnitude, from the (current) 100 microseconds to 10 milliseconds, which would be sufficient for communications over more than 100 km.