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

Journal of Modern Optics

Einstein localization in entangled light scattering

Kam Wai Clifford Chan, C. K. Law, Mikhail Vladimirovich Fedorov, Joseph H. Eberly

Published Jun 18, 2004• 3 citations
Publisher

Abstract

We discuss Einstein-Podolsky-Rosen (EPR)-type entanglement in two-particle break-up, using Raman scattering with atom recoil as an example. The Schmidt number K is used as a measure of entanglement and the conditions to acquire high entanglement are obtained. We also illustrate the EPR conditional uncertainty in a situation where Δx Δp reaches a value much smaller than the Heisenberg limit.

DOI
10.1080/09500340408232490

Related papers

Two-particle breakup and Einstein-Podolsky-Rosen entanglement

Kam Wai Clifford Chan

The problem of two-particle breakup involving Einstein- Podolsky-Rosen entanglement is studied in this thesis. One or both of the fragments in the breakup can be massive. We have examined photoionization, photodissociation, spontaneous emission, Raman scattering and Rayleigh scattering, and identified a generic control parameter that determines the degree of entanglement in these physical systems. This control parameter allows one to find the conditions to achieve very high entanglement. Similarities among the systems are also found in terms of entanglement and wave packet localization, while subtle differences in the evolution of wave packets due to the nature of the participating particles are observed. With the help of a Gaussian model, a concrete relation between entanglement and experimentally measurable quantities is established. The model also explains the apparent entanglement loss in the evolution of wave packets in free space through the notion of phase entanglement, and relates the Heisenberg uncertainty relation and Einstein- Podolsky-Rosen conditional uncertainty to the Schmidt number. It is conjectured that the Schmidt number serves as the upper or lower bound to the uncertainty relations for a generic bipartite breakup.

•Jan 1, 2005•0 citations

The Einstein-Podolsky-Rosen Paradox and Entanglement 1: Signatures of EPR correlations for continuous variables

M. D. Reid

A generalization of the 1935 Einstein-Podolsky-Rosen (EPR) argument for measurements with continuous variable outcomes is presented to establish criteria for the demonstration of the EPR paradox, for situations where the correlation between spatially separated subsystems is not perfect. Two types of criteria for EPR correlations are determined. The first type are based on measurements of the variances of conditional probability distributions and are necessary to reflect directly the situation of the original EPR paradox. The second weaker set of EPR criteria are based on the proven failure of (Bell-type) local realistic theories which could be consistent with a local quantum description for each subsystem. The relationship with criteria sufficient to prove entanglement is established, to show that any demonstration of EPR correlations will also signify entanglement. It is also shown how a demonstration of entanglement between two spatially separated subsystems, if not able to interpreted as a violation of a Bell-type inequality, may be interpreted as a demonstration of the EPR correlations. In particular it is explained how the experimental observation of two-mode squeezing using spatially separated detectors will signify not only entanglement but EPR correlations defined in a general sense.

arXiv:quant-ph/0112038•Dec 7, 2001•2 citations

Towards an Einstein–Podolsky–Rosen paradox between two macroscopic atomic ensembles at room temperature

Qiongyi He, M. D. Reid

Experiments have reported the entanglement of two spatially separated macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503; Julsgaard et al 2001 Nature 413 400). We show how an Einstein–Podolsky–Rosen (EPR) paradox is realizable with this experiment. Our proposed test involves violation of an inferred Heisenberg uncertainty principle, which is a sufficient condition for an EPR paradox. This is a stronger test of nonlocality than entanglement. Our proposal would enable the first definitive confirmation of quantum EPR paradox correlations between two macroscopic objects at room temperature. This is a necessary intermediate step towards a nonlocal experiment with causal measurement separations. As well as having fundamental significance, the realization of an atomic EPR paradox could provide a resource for novel applications in quantum technology.

arXiv:1310.7296•New Journal of Physics•Jun 20, 2013•15 citations

Generation of Einstein-Podolsky-Rosen Pairs of Atoms

E. W. Hagley, Xavier Maı̂tre, Gilles Nogues +4 more

Pairs of atoms have been prepared in an entangled state of the Einstein-Podolsky-Rosen (EPR) type. They were produced by the exchange of a single photon between the atoms in a high $Q$ cavity. The atoms, entangled in a superposition involving two different circular Rydberg states, were separated by a distance of the order of 1 cm. At variance with most previous EPR experiments, this one involves massive particles. It can be generalized to three or more atoms and opens the way to new tests of nonlocality in mesoscopic quantum systems.

Physical Review Letters•Jul 7, 1997•808 citations

Experimental demonstration of two-color Einstein–Podolsky–Rosen entanglement in a hot vapor cell

Kai Wang, Shuai Shi, Wei Zhang +6 more

Einstein–Podolsky–Rosen (EPR) entanglement, involving pairs of particles that are entangled in position and momenta, is of special importance for quantum information processing. Practical quantum communication requires a two-color entanglement source: visible-band photons used to excite atoms and the communication band used for signal transmission. In this article, we report on the first experimental demonstration of two-color EPR entanglement based on spontaneous Raman scattering thermal Rb atoms using quantum ghost interference and ghost imaging. This work adopts a fundamental experiment that assists in promoting practical quantum communications and in providing a means to perform quantum imaging.

OSA Continuum•Jul 8, 2019•2 citations

Strong Einstein-Podolsky-Rosen entanglement from a single squeezed light source

T. Eberle, Vitus Händchen, Jörg Duhme +3 more

Einstein-Podolsky-Rosen (EPR) entanglement is a criterion that is more demanding than just certifying entanglement. We theoretically and experimentally analyze the low-resource generation of bipartite continuous-variable entanglement, as realized by mixing a squeezed mode with a vacuum mode at a balanced beam splitter, i.e., the generation of so-called vacuum-class entanglement. We find that in order to observe EPR entanglement the total optical loss must be smaller than $33.3$ $%$. However, arbitrarily strong EPR entanglement is generally possible with this scheme. We realize continuous-wave squeezed light at $1550$ nm with up to $9.9$ dB of nonclassical noise reduction, which is the highest value at a telecom wavelength so far. Using two phase-controlled balanced homodyne detectors we observe an EPR covariance product of $0.502\ifmmode\pm\else\textpm\fi{}0.006<1$, where $1$ is the critical value. We discuss the feasibility of strong Gaussian entanglement and its application for quantum key distribution in a short-distance fiber network.

arXiv:1103.1817•Physical Review A•May 31, 2011•56 citations
We discuss Einstein-Podolsky-Rosen (EPR)-type entanglement in two-particle break-up, using Raman scattering with atom recoil as an example. The Schmidt number K is used as a measure of entanglement and the conditions to acquire high entanglement are obtained. We also illustrate the EPR conditional uncertainty in a situation where Δx Δp reaches a value much smaller than the Heisenberg limit.
The problem of two-particle breakup involving Einstein- Podolsky-Rosen entanglement is studied in this thesis. One or both of the fragments in the breakup can be massive. We have examined photoionization, photodissociation, spontaneous emission, Raman scattering and Rayleigh scattering, and identified a generic control parameter that determines the degree of entanglement in these physical systems. This control parameter allows one to find the conditions to achieve very high entanglement. Similarities among the systems are also found in terms of entanglement and wave packet localization, while subtle differences in the evolution of wave packets due to the nature of the participating particles are observed. With the help of a Gaussian model, a concrete relation between entanglement and experimentally measurable quantities is established. The model also explains the apparent entanglement loss in the evolution of wave packets in free space through the notion of phase entanglement, and relates the Heisenberg uncertainty relation and Einstein- Podolsky-Rosen conditional uncertainty to the Schmidt number. It is conjectured that the Schmidt number serves as the upper or lower bound to the uncertainty relations for a generic bipartite breakup.
A generalization of the 1935 Einstein-Podolsky-Rosen (EPR) argument for measurements with continuous variable outcomes is presented to establish criteria for the demonstration of the EPR paradox, for situations where the correlation between spatially separated subsystems is not perfect. Two types of criteria for EPR correlations are determined. The first type are based on measurements of the variances of conditional probability distributions and are necessary to reflect directly the situation of the original EPR paradox. The second weaker set of EPR criteria are based on the proven failure of (Bell-type) local realistic theories which could be consistent with a local quantum description for each subsystem. The relationship with criteria sufficient to prove entanglement is established, to show that any demonstration of EPR correlations will also signify entanglement. It is also shown how a demonstration of entanglement between two spatially separated subsystems, if not able to interpreted as a violation of a Bell-type inequality, may be interpreted as a demonstration of the EPR correlations. In particular it is explained how the experimental observation of two-mode squeezing using spatially separated detectors will signify not only entanglement but EPR correlations defined in a general sense.
Experiments have reported the entanglement of two spatially separated macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503; Julsgaard et al 2001 Nature 413 400). We show how an Einstein–Podolsky–Rosen (EPR) paradox is realizable with this experiment. Our proposed test involves violation of an inferred Heisenberg uncertainty principle, which is a sufficient condition for an EPR paradox. This is a stronger test of nonlocality than entanglement. Our proposal would enable the first definitive confirmation of quantum EPR paradox correlations between two macroscopic objects at room temperature. This is a necessary intermediate step towards a nonlocal experiment with causal measurement separations. As well as having fundamental significance, the realization of an atomic EPR paradox could provide a resource for novel applications in quantum technology.
Pairs of atoms have been prepared in an entangled state of the Einstein-Podolsky-Rosen (EPR) type. They were produced by the exchange of a single photon between the atoms in a high QQQ cavity. The atoms, entangled in a superposition involving two different circular Rydberg states, were separated by a distance of the order of 1 cm. At variance with most previous EPR experiments, this one involves massive particles. It can be generalized to three or more atoms and opens the way to new tests of nonlocality in mesoscopic quantum systems.
Einstein–Podolsky–Rosen (EPR) entanglement, involving pairs of particles that are entangled in position and momenta, is of special importance for quantum information processing. Practical quantum communication requires a two-color entanglement source: visible-band photons used to excite atoms and the communication band used for signal transmission. In this article, we report on the first experimental demonstration of two-color EPR entanglement based on spontaneous Raman scattering thermal Rb atoms using quantum ghost interference and ghost imaging. This work adopts a fundamental experiment that assists in promoting practical quantum communications and in providing a means to perform quantum imaging.
Einstein-Podolsky-Rosen (EPR) entanglement is a criterion that is more demanding than just certifying entanglement. We theoretically and experimentally analyze the low-resource generation of bipartite continuous-variable entanglement, as realized by mixing a squeezed mode with a vacuum mode at a balanced beam splitter, i.e., the generation of so-called vacuum-class entanglement. We find that in order to observe EPR entanglement the total optical loss must be smaller than 33.333.333.3 %. However, arbitrarily strong EPR entanglement is generally possible with this scheme. We realize continuous-wave squeezed light at 155015501550 nm with up to 9.99.99.9 dB of nonclassical noise reduction, which is the highest value at a telecom wavelength so far. Using two phase-controlled balanced homodyne detectors we observe an EPR covariance product of $0.502\ifmmode\pm\else\textpm\fi{}0.006<1$, where 111 is the critical value. We discuss the feasibility of strong Gaussian entanglement and its application for quantum key distribution in a short-distance fiber network.