Quantum teleportation over 143 kilometres using active feed-forward

• Published in: Nature (London) 2012-09, Vol.489 (7415), p.269-273
• Main Authors: Ma, Xiao-Song, Herbst, Thomas, Scheidl, Thomas, Wang, Daqing, Kropatschek, Sebastian, Naylor, William, Wittmann, Bernhard, Mech, Alexandra, Kofler, Johannes, Anisimova, Elena, Makarov, Vadim, Jennewein, Thomas, Ursin, Rupert, Zeilinger, Anton
• Format: Article
• Language: English
• Subjects: 639/705/258; 639/766/483; Applied sciences; Atoms & subatomic particles; Classical and quantum physics: mechanics and fields; Detectors; Exact sciences and technology; Experiments; Foundations, theory of measurement, miscellaneous theories (including aharonov-bohm effect, bell inequalities, berry's phase); Ground stations; Humanities and Social Sciences; Ingredients; Internet; letter; Links; Long distance; multidisciplinary; Optical telecommunications; Photons; Physics; Platforms; Position (location); Properties; Quantum computation; Quantum information; Quantum mechanics; Quantum teleportation; Quantum theory; Qubits (quantum computing); Satellite communications; Science; Science (multidisciplinary); Systems stability; Telecommunications; Telecommunications and information theory; Telescopes; Transmitters
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature11472

The benchmark for a global quantum internet — quantum teleportation of independent qubits using active feed-forward over a free-space link whose attenuation corresponds to the path between a satellite and a ground station — has now been successfully achieved over a distance of 143 km, between the Canary Islands of La Palma and Tenerife. Island hopping by quantum teleportation Since the first experimental demonstration of quantum teleportation — a central component of quantum communication and quantum computation — physicists have gradually extended the distance over which the quantum information is distributed. This paper reports long-distance quantum teleportation involving active feed-forward in real time, a feature that will be essential for future applications such as communication between quantum computers. Using two optical links, quantum and classical, quantum teleportation of an independent state was achieved across a 'record' 143 km of free space between the Canary Islands of La Palma and Tenerife. Significantly, this route bears comparison with the path between a satellite and a ground station. The quantum internet 1 is predicted to be the next-generation information processing platform, promising secure communication 2 , 3 and an exponential speed-up in distributed computation 2 , 4 . The distribution of single qubits over large distances via quantum teleportation 5 is a key ingredient for realizing such a global platform. By using quantum teleportation, unknown quantum states can be transferred over arbitrary distances to a party whose location is unknown. Since the first experimental demonstrations of quantum teleportation of independent external qubits 6 , an internal qubit 7 and squeezed states 8 , researchers have progressively extended the communication distance. Usually this occurs without active feed-forward of the classical Bell-state measurement result, which is an essential ingredient in future applications such as communication between quantum computers. The benchmark for a global quantum internet is quantum teleportation of independent qubits over a free-space link whose attenuation corresponds to the path between a satellite and a ground station. Here we report such an experiment, using active feed-forward in real time. The experiment uses two free-space optical links, quantum and classical, over 143 kilometres between the two Canary Islands of La Palma and Tenerife. To achieve this, we combine advanced techniques involving a frequ