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

arXiv:1103.2779 · Physical Review Letters

Detecting Entanglement in Spatial Interference

Clemens Gneiting, Klaus Hornberger

Published May 24, 2011• 39 citations
arXivHTMLPDF

Abstract

We discuss an experimentally amenable class of two-particle states of motion giving rise to nonlocal spatial interference under position measurements. Using the concept of modular variables, we derive a separability criterion which is violated by these non-Gaussian states. While we focus on the free motion of material particles, the presented results are valid for any pair of canonically conjugate continuous variable observables and should apply to a variety of bipartite interference phenomena.

DOI
10.1103/physrevlett.106.210501

Related papers

Quantum entanglement beyond Gaussian criteria

Rafael M. Gomes, A. Salles, Fabricio Toscano +2 more

Most of the attention given to continuous variable systems for quantum information processing has traditionally been focused on Gaussian states. However, non-Gaussianity is an essential requirement for universal quantum computation and entanglement distillation, and can improve the efficiency of other quantum information tasks. Here we report the experimental observation of genuine non-Gaussian entanglement using spatially entangled photon pairs. The quantum correlations are invisible to all second-order tests, which identify only Gaussian entanglement, and are revealed only under application of a higher-order entanglement criterion. Thus, the photons exhibit a variety of entanglement that cannot be reproduced by Gaussian states.

Proceedings of the National Academy of Sciences•Dec 8, 2009•65 citations

A general inseparability criterion for non-Gaussian states

Prasoon Kumar Shandilya, Prasanta Kumar Panigrahi

We have derived a general separability criterion for a class of two mode non-Gaussian continuous variable systems, obtained earlier using PPT, violation of which provides sufficient condition for entanglement. It has been obtained by utilizing the Cauchy-Schwarz inequality and from the basic definition of separable states. This criterion coincides with the work of Agarwal and Biswas [4] which involved inequality involving higher order correlation, for testing entanglement in non-Gaussian states.

arXiv:1707.03209•Jul 11, 2017•0 citations

Detecting multipartite spatial entanglement with modular variables

Mariana R. Barros, O. Jiménez Farías, Arne Keller +3 more

Interference phenomena of quantum systems have been studied in the context of fundamental aspects of quantum physics and are considered a necessary resource for quantum information. Here we investigate the interference of multiparticle wave packets in terms of modular variables, which is a natural and convenient way to describe two or more interfering wave functions. Through the modular-variable description, interesting phenomena appear such as the complementarity between the number of wave packets and the width of the peaks of the momentum distribution. In the multipartite case, this effect produces quantum entanglement. We derive entanglement criteria that test for bipartite entanglement in generic bipartitions of a multipartite quantum state and use these criteria to test for genuine $D$-partite entanglement.

Physical Review A•Aug 5, 2015•10 citations

Detecting genuine multipartite continuous-variable entanglement

Peter van Loock, Akira Furusawa

We derive necessary conditions in terms of the variances of position and momentum linear combinations for all kinds of separability of a multiparty multimode continuous-variable state. Their violations can be sufficient for genuine multipartite entanglement, provided the combinations contain both conjugate variables of all modes. Hence, a complete state determination, for example, by detecting the entire correlation matrix of a Gaussian state, is not needed.

arXiv:quant-ph/0212052•Physical Review A•May 29, 2003•473 citations

Nonlocal Young tests with Einstein-Podolsky-Rosen-correlated particle pairs

Clemens Gneiting, Klaus Hornberger

We evaluate the nonlocal spatial interference displayed by Einstein-Podolsky-Rosen entangled particle pairs after they pass through a double-grating arrangement. An entanglement criterion is derived which serves to certify the underlying entanglement only from the observed spatial correlations. We discuss the robustness of the scheme along with a number of possible realizations with matter waves.

arXiv:1303.1294•Physical Review A•Jul 8, 2013•13 citations

Quantum entanglement in a noncommutative system

Satyabrata Adhikari, Biswajit Chakraborty, A. S. Majumdar +1 more

We explore the effect of two-dimensional position-space noncommutativity on the bipartite entanglement of continuous-variable systems. We first extend the standard symplectic framework for studying entanglement of Gaussian states of commutative systems to the case of noncommutative systems residing in two dimensions. Using the positive partial transpose criterion for separability of bipartite states, we derive a condition on the separability of a noncommutative system that is dependent on the noncommutative parameter $\ensuremath{\theta}$. We then consider the specific example of a bipartite Gaussian state and show the quantitative reduction in entanglement originating from noncommutative dynamics. We show that such a reduction in entanglement for a noncommutative system arising from the modification of the variances of the phase-space variables (uncertainty relations) is clearly manifested between two particles that are separated by small distances.

arXiv:0811.2050•Physical Review A•Apr 30, 2009•15 citations
We discuss an experimentally amenable class of two-particle states of motion giving rise to nonlocal spatial interference under position measurements. Using the concept of modular variables, we derive a separability criterion which is violated by these non-Gaussian states. While we focus on the free motion of material particles, the presented results are valid for any pair of canonically conjugate continuous variable observables and should apply to a variety of bipartite interference phenomena.
Most of the attention given to continuous variable systems for quantum information processing has traditionally been focused on Gaussian states. However, non-Gaussianity is an essential requirement for universal quantum computation and entanglement distillation, and can improve the efficiency of other quantum information tasks. Here we report the experimental observation of genuine non-Gaussian entanglement using spatially entangled photon pairs. The quantum correlations are invisible to all second-order tests, which identify only Gaussian entanglement, and are revealed only under application of a higher-order entanglement criterion. Thus, the photons exhibit a variety of entanglement that cannot be reproduced by Gaussian states.
Interference phenomena of quantum systems have been studied in the context of fundamental aspects of quantum physics and are considered a necessary resource for quantum information. Here we investigate the interference of multiparticle wave packets in terms of modular variables, which is a natural and convenient way to describe two or more interfering wave functions. Through the modular-variable description, interesting phenomena appear such as the complementarity between the number of wave packets and the width of the peaks of the momentum distribution. In the multipartite case, this effect produces quantum entanglement. We derive entanglement criteria that test for bipartite entanglement in generic bipartitions of a multipartite quantum state and use these criteria to test for genuine DDD-partite entanglement.
We explore the effect of two-dimensional position-space noncommutativity on the bipartite entanglement of continuous-variable systems. We first extend the standard symplectic framework for studying entanglement of Gaussian states of commutative systems to the case of noncommutative systems residing in two dimensions. Using the positive partial transpose criterion for separability of bipartite states, we derive a condition on the separability of a noncommutative system that is dependent on the noncommutative parameter $\ensuremath{\theta}$. We then consider the specific example of a bipartite Gaussian state and show the quantitative reduction in entanglement originating from noncommutative dynamics. We show that such a reduction in entanglement for a noncommutative system arising from the modification of the variances of the phase-space variables (uncertainty relations) is clearly manifested between two particles that are separated by small distances.