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Related papers: Violating Bell's inequalities in the vacuum

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We consider the entanglement of orthogonal generalized Bernoulli states in two separate single-mode high-$Q$ cavities. The expectation values and the correlations of the electric field in the cavities are obtained. We then define, in each…

Quantum Physics · Physics 2009-11-11 R. Lo Franco , G. Compagno , A. Messina , A. Napoli

We show that the "practical" Bell inequalities, which use intensities as the observed variables, commonly used in quantum optics and widely accepted in the community, suffer from an inherent loophole, which severely limits the range of…

Quantum Physics · Physics 2016-10-07 Marek Zukowski , Marcin Wiesniak , Wieslaw Laskowski

In this paper we describe a test of Bell inequalities using a non- maximally entangled state, which represents an important step in the direction of eliminating the detection loophole. The experiment is based on the creation of a…

Quantum Physics · Physics 2007-05-23 M. Genovese , G. Brida , C. Novero , E. Predazzi

We analyze an all-optical setup which enables Bell-inequality violation over long distances by exploiting probabilistic entanglement swapping. The setup involves only two-mode squeezers, displacements, beamsplitters, and on/off detectors.…

We analyze entanglement between quantum interacting fields. In particular, we use R\'enyi entropy to quantify the entanglement between the fields in the ground state of the linear $\sigma$ model. We adopt R\'enyi entropy because the failure…

Quantum Physics · Physics 2015-03-17 Daniele Teresi , Giuseppe Compagno

Quantum correlations between spatially separated parts of a $d$-dimensional bipartite system ($d\geq 2$) have no classical analog. Such correlations, also called entanglements, are not only conceptually important, but also have a profound…

The entanglement between spatial regions in an interacting Bose-Einstein condensate is investigated using a quantum field theoretic formalism. Regions that are small compared to the healing length are governed by a non-relativistic quantum…

Quantum Gases · Physics 2021-04-28 N. Sánchez-Kuntz , S. Floerchinger

We discuss quantum entanglement in top pair production at the LHC. Near the $t \bar t$ threshold, entanglement observables are enhanced by suppressing the contribution of $q \bar q$ subprocesses, which is achieved by a simple cut on the…

High Energy Physics - Phenomenology · Physics 2022-08-24 J. A. Aguilar-Saavedra , J. A. Casas

We demonstrate how to efficiently derive a broad class of inequalities for entanglement detection in multi-mode continuous variable systems. The separability conditions are established from partial transposition (PT) in combination with…

Quantum Physics · Physics 2015-05-13 Qingqing Sun , Hyunchul Nha , M. Suhail Zubairy

Multiparticle entanglement is a valuable resource for quantum technologies, including measurement based quantum computing, quantum secret sharing, and a variety of quantum sensing applications. The direct way to detect this resource is to…

Quantum Physics · Physics 2025-10-28 Dian Wu , Fei Shi , Jia-Cheng Sun , Bo-Wen Wang , Xue-Mei Gu , Giulio Chiribella , Qi Zhao , Jian Wu

A method is introduced whereby two non-interacting quantum subsystems, that each interact with a third subsystem, are entangled via repeated projective measurements of the state of the third subsystem. A variety of physical examples are…

Quantum Physics · Physics 2007-05-23 Lian-Ao Wu , Daniel A. Lidar , Sara Schneider

We study the phenomenon of entanglement extraction from the vacuum of a massless scalar field in $(1+1)$ dimensional spacetime in presence of a moving Dirichlet boundary condition, i.e. mirror spacetime, using two inertial Unruh-DeWitt…

Quantum Physics · Physics 2019-07-11 Wan Cong , Erickson Tjoa , Robert B. Mann

Quantum nonlocality is tested for an entangled coherent state, interacting with a dissipative environment. A pure entangled coherent state violates Bell's inequality regardless of its coherent amplitude. The higher the initial nonlocality,…

Quantum Physics · Physics 2009-11-07 D. Wilson , H. Jeong , M. S. Kim

We study the role that both vacuum fluctuations and vacuum entanglement of a scalar field play in identifying the spacetime topology, which is not prescribed from first principles---neither in general relativity or quantum gravity. We…

Quantum Physics · Physics 2016-02-10 Eduardo Martin-Martinez , Alexander R. H. Smith , Daniel R. Terno

An experimental test of Bell's inequality allows ruling out any local-realistic description of nature by measuring correlations between distant systems. While such tests are conceptually simple, there are strict requirements concerning the…

We study entanglement harvested from a quantum field through local interaction with Unruh-DeWitt detectors undergoing linear acceleration. The interactions allow entanglement to be swapped locally from the field to the detectors. We find an…

Quantum Physics · Physics 2017-10-19 Grant Salton , Robert B. Mann , Nicolas C. Menicucci

We analyze correlations between pairs of particle detectors quadratically coupled to a real scalar field. We find that, while a single quadratically coupled detector presents no divergences, when one considers pairs of detectors there…

Quantum Physics · Physics 2017-11-08 Allison Sachs , Robert B. Mann , Eduardo Martin-Martinez

We propose an experimental scheme for the measurement of entanglement between two two-level atoms. Our scheme requires one of the two entangled atoms to interact with a cavity field dispersively, and we show that by measuring the zero…

Quantum Physics · Physics 2022-06-29 Nilakantha Meher , M. Bhattacharya , Anand K. Jha

It has been argued more than 30 years ago that it is not possible to test locality at colliders, due to the inability to directly measure non-commutating observables such as spin components in current collider experiments. Recently, there…

High Energy Physics - Phenomenology · Physics 2025-12-05 Philip Bechtle , Cedric Breuning , Herbi K. Dreiner , Claude Duhr

Bell inequality tests based on high-dimensional entanglement usually require measurements that can resolve multiple possible outcomes. However, the implementation of high-dimensional multi-outcome measurements is often only emulated via a…