Long-Distance Free-Space Distribution of Quantum Entanglement

We demonstrate the distribution of quantum entanglement via optical free-space links to independent receivers separated by 600 m, with no line of sight between each other. A Bell inequality between those receivers is violated by more than four standard deviations, confirming the quality of the entanglement. This outdoor experiment represents a step toward satellite-based distributed quantum entanglement.

[1]  E. Schrödinger.  Die gegenwärtige Situation in der Quantenmechanik , 1935, Naturwissenschaften.

[2]  Harald Weinfurter,et al.  Quantum communications in space , 2003, 2003 European Quantum Electronics Conference. EQEC 2003 (IEEE Cat No.03TH8665).

[3]  H. Sauerzopf,et al.  Optical characteristics of the aerosol in Spain and Austria and its effect on radiative forcing , 2002 .

[4]  P R Tapster,et al.  erratum , 2002, Nature.

[5]  H. Bechmann-Pasquinucci,et al.  Quantum cryptography , 2001, quant-ph/0101098.

[6]  Weinfurter,et al.  Quantum cryptography with entangled photons , 1999, Physical review letters.

[7]  D. Bouwmeester,et al.  The Physics of Quantum Information , 2000 .

[8]  Wolfgang Dür,et al.  Quantum Repeaters: The Role of Imperfect Local Operations in Quantum Communication , 1998 .

[9]  H. Weinfurter,et al.  Violation of Bell's Inequality under Strict Einstein Locality Conditions , 1998, quant-ph/9810080.

[10]  N. Gisin,et al.  Violation of Bell Inequalities by Photons More Than 10 km Apart , 1998, quant-ph/9806043.

[11]  Richard J. Hughes,et al.  Practical free-space quantum key distribution over 1 km , 1998, quant-ph/9805071.

[12]  N. Gisin,et al.  OPTIMAL EAVESDROPPING IN QUANTUM CRYPTOGRAPHY. I. INFORMATION BOUND AND OPTIMAL STRATEGY , 1997 .

[13]  Shih,et al.  New high-intensity source of polarization-entangled photon pairs. , 1995, Physical review letters.

[14]  Rarity,et al.  Violation of Bell's inequality over 4 km of optical fiber. , 1994, Physical review letters.

[15]  Charles H. Bennett,et al.  Quantum cryptography without Bell's theorem. , 1992, Physical review letters.

[16]  Ekert,et al.  Quantum cryptography based on Bell's theorem. , 1991, Physical review letters.

[17]  A. Shimony,et al.  Proposed Experiment to Test Local Hidden Variable Theories. , 1969 .