English
Related papers

Related papers: Validation of entanglement purification by continu…

200 papers

We propose three criteria for identifying continuous variable entanglement between two many-particle systems with no restrictions on the quantum state of the local oscillators used in the measurements. Mistakenly asserting a coherent state…

Quantum Physics · Physics 2009-11-13 A. J. Ferris , M. K. Olsen , E. G. Cavalcanti , M. J. Davis

We report on the quantification of entanglement by means of entanglement measures on a four- and a six- qubit cluster state realized by using photons entangled both in polarization and linear momentum. This paper also addresss the question…

Quantum Physics · Physics 2011-03-23 H. Wunderlich , G. Vallone , P. Mataloni , M. B. Plenio

The ability to filter quantum states is a key capability in quantum information science and technology, in which one-qubit filters, or polarizers, have found wide application. Filtering on the basis of entanglement requires extension to…

We establish contact between the delocalization properties of pure quantum states, as quantified by their number of principal components, and the average generalized entanglement properties, as quantified by purity measures relative to…

Quantum Physics · Physics 2009-11-13 Lorenza Viola , Winton G. Brown

Partial polarization is the manifestation of the correlation between two mutually orthogonal transverse field components associated with a light beam. We show both theoretically and experimentally that the origin of this correlation can be…

We present a significantly improved scheme of entanglement detection inspired by local uncertainty relations for a system consisting of two qubits. Developing the underlying idea of local uncertainty relations, namely correlations, we…

Quantum Physics · Physics 2016-08-16 Christian Kothe , Gunnar Björk

The experimental detection of quantum entanglement is of great importance in quantum information processing. We present two separability criteria based on the generalized realignment moments. By incorporating additional parameters, these…

Quantum Physics · Physics 2026-02-25 Xiaofen Huang , Xishun Zhu , Bin Chen , Naihuan Jing , Shao-Ming Fei

Detection of entanglement in quantum states is one of the most important problems in quantum information processing. However, it is one of the most challenging tasks to find a universal scheme which is also desired to be optimal to detect…

Quantum Physics · Physics 2026-03-13 Arijit Dutta , Sibasish Ghosh , Jaewan Kim , Ritabrata Sengupta

We formulate the classical polarization theory for light by using entanglement analysis. We demonstrate a route to a systematic and consistent measure of ordinary light polarization that extends automatically to a new understanding of the…

Optics · Physics 2011-11-02 X. F. Qian , J. H. Eberly

We introduce a class of bipartite entangled continuous variable states that are positive under partial transposition operation, i.e., PPT bound entangled. These states are based on realistic preparation procedures in optical systems, being…

Quantum Physics · Physics 2015-06-15 F. E. S. Steinhoff , M. C. de Oliveira , J. Sperling , W. Vogel

Multipartite entangled states are a fundamental resource for a wide range of quantum information processing tasks. In particular, in quantum networks it is essential for the parties involved to be able to verify if entanglement is present…

We propose an operational degree of polarization in terms of the variance of the projected Stokes vector minimized over all the directions of the Poincar\'e sphere. We examine the properties of this degree and show that some problems…

We propose experimentally feasible separability criteria for bipartite systems based on local symmetric measurements. Through detailed examples, we demonstrate that our criteria can detect entanglement more effectively compared to existing…

Quantum Physics · Physics 2025-12-12 Yu Lu , Wen Zhou , Meng Su , Hong-Xing Wu , Shao-Ming Fei , Zhi-Xi Wang

We present conditions every measure of entanglement has to satisfy and construct a whole class of 'good' entanglement measures. The generalization of our class of entanglement measures to more than two particles is straightforward. We…

Quantum Physics · Physics 2009-01-23 V. Vedral , M. B. Plenio , M. A. Rippin , P. L. Knight

Gradual loss of the entanglement of a twin beam containing around 25 photon pairs with the increasing external noise is experimentally investigated. The entanglement is quantified by the non-classicality depths and the non-classicality…

Quantum Physics · Physics 2020-08-12 Vaclav Michalek , Jan Perina , Ondrej Haderka

The accurate and efficient detection of quantum entanglement remains a central challenge in quantum information science. In this work, we study the detection of entanglement of polarized photons for measurement devices that are solely…

Quantum Physics · Physics 2025-12-19 Marlene Funck , Ilija Funk , Tizian Schmidt , René Schwonnek

We present a theoretical study of entanglement in ensembles consisting of an arbitrary number of particles. Multipartite entanglement criteria in terms of observables are formulated for a fixed number of particles as well as for systems…

Quantum Physics · Physics 2017-06-22 J. Sperling , I. A. Walmsley

Entanglement is fundamental inasmuch because it rephrases the quest for the classical-quantum demarcation line, and it also has potentially enormous practical applications in modern information technology. In this work, employing the…

Quantum Physics · Physics 2024-06-26 Xiaofen Huang , Tinggui Zhang , Naihuan Jing

Three different methods have been discussed to verify continuous variable entanglement of intense light beams. We demonstrate all three methods using the same set--up to facilitate the comparison. The non--linearity used to generate…

Quantum Physics · Physics 2009-11-11 O. Glöckl , U. L. Andersen , G. Leuchs

Using a spontaneous parametric-downconversion source of photon pairs, we are working towards the creation of arbitrary 2-qubit quantum states with high fidelity. Currently, all physically allowable combinations of polarization entanglement…

Quantum Physics · Physics 2007-05-23 Paul Kwiat , Joe Altepeter , David Branning , Evan Jeffrey , Nicholas Peters , Tzu-Chieh Wei