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Related papers: How to construct entanglement witnesses

200 papers

We study the optimal entanglement witness with respect to multiqubits W-states. We show such entanglement witnesses can be used to distinguish genuine entangled states, different biseparable states and fully separable states.

Quantum Physics · Physics 2015-05-13 Ming-Jing Zhao , Zhi-Xi Wang , Shao-Ming Fei

To address the outstanding task of detecting entanglement in large quantum systems, entanglement witnesses have emerged, addressing the separable nature of a state. Yet optimizing witnesses, or accessing them experimentally, often remains a…

We propose a family of positive maps constructed from a recently introduced class of symmetric measurements. These maps are used to define entanglement witnesses, which include other popular approaches with mutually unbiased bases and…

Quantum Physics · Physics 2022-02-09 Katarzyna Siudzińska

We derive a set of algebraic equations, the so-called multipartite separability eigenvalue equations. Based on their solutions, we introduce a universal method for the construction of multipartite entanglement witnesses. We witness…

Quantum Physics · Physics 2015-06-15 J. Sperling , W. Vogel

Entanglement, while being critical in many quantum applications, is difficult to characterize experimentally. While entanglement witnesses based on the fidelity to the target entangled state are efficient detectors of entanglement, they in…

Quantum Physics · Physics 2020-01-29 Won Kyu Calvin Sun , Alexandre Cooper , Paola Cappellaro

An entanglement witness (EW) is a Hermitian operator that can distinguish an entangled state from all separable states. We drive and implement a numerical method based on machine learning to create a multipartite EW. Using support vector…

Quantum Physics · Physics 2025-04-28 Mahmoud Mahdian , Zahra Mousavi

In quantum information theory, the reliable and effective detection of entanglement is of paramount importance. However, given an unknown state, assessing its entanglement is a challenging task. To attack this problem, we investigate the…

Quantum Physics · Physics 2015-12-09 Jochen Szangolies , Hermann Kampermann , Dagmar Bruß

Entanglement detection problem is one of the important problem in quantum information theory. Gurvit showed that this problem is NP complete and thus this may be the possible reason that only one criterion is not sufficient to detect all…

Quantum Physics · Physics 2023-01-25 Shruti Aggarwal , Satyabrata Adhikari

Linear and nonlinear entanglement witnesses for a given bipartite quantum systems are constructed. Using single particle feasible region, a way of constructing effective entanglement witnesses for bipartite systems is provided by exact…

Quantum Physics · Physics 2009-10-29 M. A. Jafarizadeh , A. Heshmati , K. Aghayara

We give a universal recipe for constructing nonlinear entanglement witnesses able to detect non-classical correlations in arbitrary systems of distinguishable and/or identical particles for an arbitrary number of constituents. The…

Quantum Physics · Physics 2013-05-29 Marcin Kotowski , Michal Kotowski , Marek Kus

We introduce an approach which allows a detailed structural and quantitative analysis of multipartite entanglement. The sets of states with different structures are convex and nested. Hence, they can be distinguished from each other using…

Quantum Physics · Physics 2014-12-31 F. Shahandeh , J. Sperling , W. Vogel

Entanglement witnesses provide a standard tool for the analysis of entanglement in experiments. We investigate possible nonlinear entanglement witnesses from several perspectives. First, we demonstrate that they can be used to show that the…

Quantum Physics · Physics 2007-06-13 Otfried Gühne , Norbert Lütkenhaus

We present the experimental detection of genuine multipartite entanglement using entanglement witness operators. To this aim we introduce a canonical way of constructing and decomposing witness operators so that they can be directly…

In this paper we introduce a criterion for the characterization of Entanglement Witness for multipartite quantum systems. Our approach is based on the characterization of the "tangent space" to the set of pure product states.

Quantum Physics · Physics 2012-10-30 Fabio Masillo

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

We construct three-qubit entanglement witnesses with relatively simple structures. Despite their simplicity, these witnesses are capable of detecting a number of bound entangled states more effectively. To illustrate this, two families of…

Quantum Physics · Physics 2017-06-13 Yahya Akbari-Kourbolagh

We consider multipartite quantum state discrimination and show that the minimum-error discrimination by separable measurements is closely related to the concept of entanglement witness. Based on the properties of entanglement witness, we…

Quantum Physics · Physics 2023-04-25 Donghoon Ha , Jeong San Kim

We discuss the problem of determining whether the state of several quantum mechanical subsystems is entangled. As in previous work on two subsystems we introduce a procedure for checking separability that is based on finding state…

Quantum Physics · Physics 2007-05-23 Andrew C. Doherty , Pablo A. Parrilo , Federico M. Spedalieri

We present a method to certify the entanglement of all bipartite entangled quantum states in a device-independent way. This is achieved by placing the state in a quantum network and constructing a correlation inequality based on an…

Quantum Physics · Physics 2018-12-04 Joseph Bowles , Ivan Šupić , Daniel Cavalcanti , Antonio Acín

We introduce informationally complete measurements whose outcomes are entanglement witnesses and so answer the question of how many witnesses need to be measured to decide whether an arbitrary state is entangled or not: as many as the…

Quantum Physics · Physics 2015-05-13 Huangjun Zhu , Yong Siah Teo , Berthold-Georg Englert