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Related papers: Optimal entanglement witnesses based on local orth…

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Continuous-variable Gaussian entanglement is an attractive notion, both as a fundamental concept in quantum information theory, based on the well-established Gaussian formalism for phase-space variables, and as a practical resource in…

Quantum Physics · Physics 2026-05-07 E. Shchukin , P. van Loock

We describe a general method of realizing entanglement witnesses in terms of the interference pattern of a single quantum probe. After outlining the principle, we discuss specific realizations both with electrons in mesoscopic Aharonov-Bohm…

Quantum Physics · Physics 2008-09-23 T. Scholak , F. Mintert , C. A. Müller

We propose a scheme for witnessing entanglement in phase space by significantly inefficient detectors. The implementation of this scheme does not require any additional process for correcting errors in contrast to previous proposals.…

Quantum Physics · Physics 2010-01-06 Seung-Woo Lee , Hyunseok Jeong , Dieter Jaksch

We compute all third-order local invariants accessible via randomised measurements and employ them to derive separability criteria. The reconstruction of the invariants yields experimentally accessible entanglement criteria for multipartite…

Quantum Physics · Physics 2025-06-25 Giovanni Scala , Anindita Bera , Gniewomir Sarbicki

There exists, in general, a convex set of quantum state estimators that maximize the likelihood for informationally incomplete data. We propose an estimation scheme, catered to measurement data of this kind, to search for the exact…

Bell inequalities, considered within quantum mechanics, can be regarded as non-optimal witness operators. We discuss the relationship between such Bell witnesses and general entanglement witnesses in detail for the Bell inequality derived…

Quantum Physics · Physics 2009-11-11 P. Hyllus , O. Guehne , D. Bruss , M. Lewenstein

In this paper, we discuss extremal extensions of entanglement witnesses based on Choi's map. The constructions are based on a generalization of the Choi map due to Osaka, from which we construct entanglement witnesses. These extremal…

Quantum Physics · Physics 2014-08-06 R. Sengupta , Arvind

We study the entanglement properties of quantum hypergraph states of $n$ qubits, focusing on multipartite entanglement. We compute multipartite entanglement for hypergraph states with a single hyperedge of maximum cardinality, for…

Quantum Physics · Physics 2018-01-17 Maddalena Ghio , Daniele Malpetti , Matteo Rossi , Dagmar Bruß , Chiara Macchiavello

We construct entanglement witnesses using fundamental quantum operators of spin models which contain two-particle interactions and posses a certain symmetry. By choosing the Hamiltonian as such an operator, our method can be used for…

Quantum Physics · Physics 2016-01-29 Geza Toth

We show how to quantify tri-partite entanglement using entropies derived from experimental correlations. We use a multi-partite generalization of the entanglement of formation that is greater than zero if and only if the state is genuinely…

Quantum Physics · Physics 2020-11-04 James Schneeloch , Christopher C. Tison , Michael L. Fanto , Shannon Ray , Paul M. Alsing

We introduce two families of criteria for detecting and quantifying the entanglement of a bipartite quantum state of arbitrary local dimension. The first is based on measurements in mutually unbiased bases and the second is based on…

Quantum Physics · Physics 2023-11-08 Simon Morelli , Marcus Huber , Armin Tavakoli

Entanglement, a critical resource for quantum information processing, needs to be witnessed in many practical scenarios. Theoretically, witnessing entanglement is by measuring a special Hermitian observable, called entanglement witness…

Quantum Physics · Physics 2016-04-20 Xiao Yuan , Quanxin Mei , Shan Zhou , Xiongfeng Ma

Entanglement is solely a quantum property and it can be extremely helpful to test the physics beyond the Standard Model in tabletop experiments with the advent of future quantum technologies. In this work, we provide an entanglement-based…

Quantum Physics · Physics 2025-11-20 Pablo Guillermo Carmona Rufo , Ayush Kumar , Carlos Sabín , Anupam Mazumdar

We formulate an entanglement criterion using Peres-Horodecki positive partial transpose operations combined with the Schr\"odinger-Robertson uncertainty relation. We show that any pure entangled bipartite and tripartite state can be…

Quantum Physics · Physics 2009-11-13 J. Gillet , T. Bastin , G. S. Agarwal

We present an analysis of the properties and characteristics of weakly optimal entanglement witnesses, that is witnesses whose expectation value vanishes on at least one product vector. Any weakly optimal entanglement witness can be written…

Quantum Physics · Physics 2015-07-16 Bang-Hai Wang , Hai-Ru Xu , Steve Campbell , Simone Severini

Strong quantum nonlocality was introduced recently as a stronger manifestation of nonlocality in multipartite systems through the notion of local irreducibility in all bipartitions. Known existence results for sets of strongly nonlocal…

Quantum Physics · Physics 2020-10-07 Fei Shi , Mengyao Hu , Lin Chen , Xiande Zhang

Based on correlations of coherently displaced photon-numbers, we derive entanglement criteria for the purpose to verify non-Gaussian entanglement. Our construction method enables us to verify bipartite and multipartite entanglement of…

Quantum Physics · Physics 2017-09-08 B. Kühn , W. Vogel , J. Sperling

An entanglement witness is an observable detecting entanglement for a subset of states. We present a framework that makes an entanglement witness twice as powerful due to the general existence of a second (lower) bound, in addition to the…

Quantum Physics · Physics 2020-02-20 Joonwoo Bae , Dariusz Chruściński , Beatrix C. Hiesmayr

Despite great efforts, an unambiguous demonstration of entanglement of mobile electrons in solid state conductors is still lacking. Investigating theoretically a generic entangler-detector setup, we here show that a witness of entanglement…

Mesoscale and Nanoscale Physics · Physics 2017-01-25 F. Brange , O. Malkoc , P. Samuelsson

Entanglement witnesses (EWs) are a fundamental tool for the detection of entanglement. We investigate the inertias of bipartite EWs constructed by the partial transpose of NPT states. Furthermore, we find out most of the inertias of the…

Quantum Physics · Physics 2022-04-21 Changchun Feng , Lin Chen , Chang Xu , Yi Shen
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