Entanglement swapping with high coherence photon pair sources

The distance in quantum communication is limited for direct transmission, but can be increased by the means of entanglement swapping implemented in a quantum relay1 or quantum repeater configuration.2 Apart from this, entanglement swapping is an intriguing phenomenon in quantum physics and deserves thus by itself to be demonstrated in an experiment. Here we present an entanglement swapping experiment realized for the first time with autonomous CW-sources.

[1]  O. Okunev,et al.  Superconducting single-photon detectors designed for operation at 1.55-µm telecommunication wavelength , 2006 .

[2]  Gregor Weihs,et al.  Experimental nonlocality proof of quantum teleportation and entanglement swapping. , 2002, Physical review letters.

[3]  Experimental synchronization of independent entangled photon sources. , 2005, Physical review letters.

[4]  J. D. Franson,et al.  Quantum relays and noise suppression using linear optics , 2002 .

[5]  B. Yurke,et al.  Bell's-inequality experiments using independent-particle sources. , 1992, Physical review. A, Atomic, molecular, and optical physics.

[6]  N. Gisin,et al.  Pulsed Energy-Time Entangled Twin-Photon Source for Quantum Communication , 1999 .

[7]  H. Weinfurter,et al.  Experimental Entanglement Swapping: Entangling Photons That Never Interacted , 1998 .

[8]  Pramod S. Joag,et al.  Separability criterion for multipartite quantum states based on the Bloch representation of density matrices , 2007, Quantum Inf. Comput..

[9]  N. Gisin,et al.  Low jitter up-conversion detectors for telecom wavelength GHz QKD , 2006 .

[10]  N. Gisin,et al.  Four-photon correction in two-photon Bell experiments , 2004, quant-ph/0407189.

[11]  Pérès.  Separability Criterion for Density Matrices. , 1996, Physical review letters.

[12]  N. Gisin,et al.  Long-distance entanglement swapping with photons from separated sources , 2004, quant-ph/0409093.

[13]  J. Cirac,et al.  Long-distance quantum communication with atomic ensembles and linear optics , 2001, Nature.

[14]  N. Gisin,et al.  Quantum relays for long distance quantum cryptography , 2003, quant-ph/0311101.

[15]  Ekert,et al.  "Event-ready-detectors" Bell experiment via entanglement swapping. , 1993, Physical review letters.

[16]  G. Grosche,et al.  Polarization dependent wavelength shift and new polarization modulation locking for phase-shifted fiber Bragg gratings , 2004, Optical Fiber Communication Conference, 2004. OFC 2004.

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

[18]  Hong,et al.  Measurement of subpicosecond time intervals between two photons by interference. , 1987, Physical review letters.