Photon-photon entanglement with a single trapped atom.
An experiment is performed where a single rubidium atom trapped within a high-finesse optical cavity emits two independently triggered entangled photons. The entanglement is mediated by the atom and is characterized both by a Bell inequality violation of S=2.5, as well as full quantum-state tomography, resulting in a fidelity exceeding F=90%. The combination of cavity-QED and trapped atom techniques makes our protocol inherently deterministic--an essential step for the generation of scalable entanglement between the nodes of a distributed quantum network.
Weber
B
B
Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
Specht
H P
HP
Müller
T
T
Bochmann
J
J
Mücke
M
M
Moehring
D L
DL
Rempe
G
G