Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Bulletin of the American Physical Society

Path Entangled Photons from Parametric Down-Conversion

H. S. Eisenberg, Juan F. Hodelin, G. Khoury, Dirk Bouwmeester

Published Mar 24, 2005• 0 citations
OpenAlex

Abstract

Using stimulated parametric down-conversion, we propose a method for generating multiphoton path entanglement. By a special coincidence detection at one down-converted arm, the photons of the second arm non-locally bunch into the desired state. Experimental demonstration for the case of two photons is presented, as well as how to extend the scheme to any number of photons.

Related papers

Path entangled photons from parametric down-conversion

H. S. Eisenberg, Juan F. Hodelin, G. Khoury +1 more

Using stimulated parametric down-conversion, we propose a method for generating multiphoton path entanglement. By a special coincidence detection at one down-converted arm, the photons of the second arm non-locally bunch into the desired state. Experimental demonstration for the case of two photons is presented, as well as how to extend the scheme to any number of photons.

Quantum Electronics and Laser Science Conference•Dec 10, 2005•0 citations

Multiphoton Path Entanglement by Nonlocal Bunching

H. S. Eisenberg, Juan F. Hodelin, G. Khoury +1 more

Multiphoton path entanglement is created without applying postselection, by manipulating the state of stimulated parametric down-conversion. A specific measurement on one of the two output spatial modes leads to the nonlocal bunching of the photons of the other mode, forming the desired multiphoton path entangled state. We present experimental results for the case of a heralded two-photon path entangled state and show how to extend this scheme to higher photon numbers.

arXiv:quant-ph/0410093•Physical Review Letters•Mar 10, 2005•94 citations

Generation of the four-photon W state and other multiphoton entangled states using parametric down-conversion

Hideharu Mikami, Yongmin Li, Takayoshi Kobayashi

We propose two interesting methods of generating the four-photon $W$ state. These methods use parametric down-conversion processes, linear optical elements, and commercial photon detectors, which are readily feasible under current technology. They can also be used to generate the three-photon $W$ state, the three-photon Greenberger-Horne-Zeilinger state, and the three-photon maximally entangled photon-number state (a typical photon-number entanglement state) by simply changing some experimental components or their parameters. Moreover, assuming we have photon number-resolving detectors, these methods can develop into methods that generate a general $n$-photon $W$ state. They are expected to become powerful tools for experimental investigations of multipartite entanglement and its applications to quantum information processing.

Physical Review A•Nov 9, 2004•63 citations

Generation of the Four-Photon W State and Other Multiphoton-Entangled States Using Parametric Down-Conversion

Takayoshi Kobayashi

We propose two interesting methods of generating the four-photon W state. These methods use parametric down-conversion processes, linear optical elements, and commercial photon detectors, which are readily feasible under current technology. They can also be used to generate the three-photon W state, the three-photon Greenberger–Horne–Zeilinger state, and the three-photon maximally entangled photon-number state (a typical photon-number entanglement state) by simply changing some experimental components or their parameters. Moreover, assuming we have photon number-resolving detectors, these methods can develop into methods that generate a general n -photon W state. They are expected to become powerful tools for experimental investigations of multipartite entanglement and its applications to quantum information processing.

CRC Press eBooks•Oct 15, 2025•0 citations

Proposal for Inverting the Quantum Cloning of Photons

Sadegh Raeisi, Wolfgang Tittel, Christoph Simon

We propose an experiment where a photon is first cloned by stimulated parametric down-conversion, making many (imperfect) copies, and then the cloning transformation is inverted, regenerating the original photon while destroying the copies. Focusing on the case where the initial photon is entangled with another photon, we study the conditions under which entanglement can be proven in the final state. The proposed experiment would provide a clear demonstration that quantum information is preserved in quantum cloning. It would furthermore allow a definitive experimental proof for micro-macro entanglement in the intermediate multiphoton state, which is still an outstanding challenge. Finally, it might provide a quantum detection technique for small differences in transmission (e.g., in biological samples), whose sensitivity scales better with the number of photons used than a classical transmission measurement.

arXiv:1111.7283•Physical Review Letters•Mar 22, 2012•18 citations

Quantum Entanglement of a Large Number of Photons

H. S. Eisenberg, G. Khoury, Gabriel A. Durkin +2 more

A bipartite multiphoton entangled state is created through stimulated parametric down-conversion of strong laser pulses in a nonlinear crystal. It is shown how detectors that do not resolve the photon number can be used to analyze such multiphoton states. Entanglement of up to 12 photons is detected using both the positivity of the partially-transposed density matrix and a newly derived criteria. Furthermore, evidence is provided for entanglement of up to 100 photons. The multiparticle quantum state is such that even in the case of an overall photon collection and detection efficiency as low as a few percent, entanglement remains and can be detected.

arXiv:quant-ph/0408030•Physical Review Letters•Nov 4, 2004•137 citations
Using stimulated parametric down-conversion, we propose a method for generating multiphoton path entanglement. By a special coincidence detection at one down-converted arm, the photons of the second arm non-locally bunch into the desired state. Experimental demonstration for the case of two photons is presented, as well as how to extend the scheme to any number of photons.
We propose two interesting methods of generating the four-photon WWW state. These methods use parametric down-conversion processes, linear optical elements, and commercial photon detectors, which are readily feasible under current technology. They can also be used to generate the three-photon WWW state, the three-photon Greenberger-Horne-Zeilinger state, and the three-photon maximally entangled photon-number state (a typical photon-number entanglement state) by simply changing some experimental components or their parameters. Moreover, assuming we have photon number-resolving detectors, these methods can develop into methods that generate a general nnn-photon WWW state. They are expected to become powerful tools for experimental investigations of multipartite entanglement and its applications to quantum information processing.
We propose two interesting methods of generating the four-photon W state. These methods use parametric down-conversion processes, linear optical elements, and commercial photon detectors, which are readily feasible under current technology. They can also be used to generate the three-photon W state, the three-photon Greenberger–Horne–Zeilinger state, and the three-photon maximally entangled photon-number state (a typical photon-number entanglement state) by simply changing some experimental components or their parameters. Moreover, assuming we have photon number-resolving detectors, these methods can develop into methods that generate a general n -photon W state. They are expected to become powerful tools for experimental investigations of multipartite entanglement and its applications to quantum information processing.
We propose an experiment where a photon is first cloned by stimulated parametric down-conversion, making many (imperfect) copies, and then the cloning transformation is inverted, regenerating the original photon while destroying the copies. Focusing on the case where the initial photon is entangled with another photon, we study the conditions under which entanglement can be proven in the final state. The proposed experiment would provide a clear demonstration that quantum information is preserved in quantum cloning. It would furthermore allow a definitive experimental proof for micro-macro entanglement in the intermediate multiphoton state, which is still an outstanding challenge. Finally, it might provide a quantum detection technique for small differences in transmission (e.g., in biological samples), whose sensitivity scales better with the number of photons used than a classical transmission measurement.
A bipartite multiphoton entangled state is created through stimulated parametric down-conversion of strong laser pulses in a nonlinear crystal. It is shown how detectors that do not resolve the photon number can be used to analyze such multiphoton states. Entanglement of up to 12 photons is detected using both the positivity of the partially-transposed density matrix and a newly derived criteria. Furthermore, evidence is provided for entanglement of up to 100 photons. The multiparticle quantum state is such that even in the case of an overall photon collection and detection efficiency as low as a few percent, entanglement remains and can be detected.