Free-Space distribution of entanglement and single photons over 144 km

Free-Space distribution of entanglement and single photons over 144 km

| R. Ursin, F. Tiefenbacher, T. Schmitt-Manderbach, H. Weier, T. Scheidl, M. Lindenthal, B. Blauensteiner, T. Jennewein, J. Perdigues, P. Trojek, B. Ömer, M. Fürst, M. Meyenburg, J. Rarity, Z. Sodnik, C. Barbieri, H. Weinfurter, A. Zeilinger
This paper reports the successful distribution of entanglement and single photons over a free-space link between the Canary Islands of La Palma and Tenerife, a distance of 144 km. The experiment, conducted by a team from various institutions, aimed to verify the feasibility of quantum communication over long distances using free-space links. The setup involved generating polarization-entangled photon pairs on La Palma, with one photon detected locally and the other transmitted via a 150 mm lens to a transmitter telescope on Tenerife. The transmitted photon was then directed to the Optical Ground Station (OGS) of the European Space Agency (ESA) on Tenerife, where it was detected by a 1 m Richey-Chrétien/Coudé telescope. The experiment demonstrated a violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality, confirming genuine quantum correlations between the two locations. Additionally, the entangled pairs were used to generate a quantum cryptographic key, achieving a secure key length of 178 bits. The results show that the setup can be adapted for quantum communication protocols and lay the groundwork for a worldwide network of quantum communication.This paper reports the successful distribution of entanglement and single photons over a free-space link between the Canary Islands of La Palma and Tenerife, a distance of 144 km. The experiment, conducted by a team from various institutions, aimed to verify the feasibility of quantum communication over long distances using free-space links. The setup involved generating polarization-entangled photon pairs on La Palma, with one photon detected locally and the other transmitted via a 150 mm lens to a transmitter telescope on Tenerife. The transmitted photon was then directed to the Optical Ground Station (OGS) of the European Space Agency (ESA) on Tenerife, where it was detected by a 1 m Richey-Chrétien/Coudé telescope. The experiment demonstrated a violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality, confirming genuine quantum correlations between the two locations. Additionally, the entangled pairs were used to generate a quantum cryptographic key, achieving a secure key length of 178 bits. The results show that the setup can be adapted for quantum communication protocols and lay the groundwork for a worldwide network of quantum communication.
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[slides and audio] Free-Space distribution of entanglement and single photons over 144 km