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Related papers: Identification of three-qubit entanglement

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We propose an ordered set of experimentally accessible conditions for detecting entanglement in mixed states. The $k$-th condition involves comparing moments of the partially transposed density operator up to order $k$. Remarkably, the…

In this paper, an intuitive mathematical formulation is provided to generalize the residual entanglement for tripartite systems of qubits (Phys. Rev. A \textbf{61}, 052306 (2000)) to the tripartite systems in higher dimension. The spirit…

Quantum Physics · Physics 2007-05-23 Chang-shui Yu He-shan Song

Entangled many-body states are an essential resource for quantum computing and interferometry. Determining the type of entanglement present in a system usually requires access to an exponential number of parameters. We show that in the case…

Quantum Physics · Physics 2014-11-17 Michael Walter , Brent Doran , David Gross , Matthias Christandl

We investigate separability and entanglement of mixed states in ${\cal C}^2\otimes{\cal C}^2\otimes{\cal C}^N$ three party quantum systems. We show that all states with positive partial transposes that have rank $\le N$ are separable. For…

Quantum Physics · Physics 2009-11-07 S. Karnas , M. Lewenstein

All the states of N qubits can be classified into N-1 entanglement classes from 2-entangled to N-entangled (fully entangled) states. Each class of entangled states is characterized by an entanglement index that depends on the partition of…

Quantum Physics · Physics 2016-11-10 Sixia Yu , Zeng-Bing Chen , Jian-Wei Pan , Yong-De Zhang

We study the distinguishability of bipartite quantum states by Positive Operator-Valued Measures with positive partial transpose (PPT POVMs). The contributions of this paper include: (1). We give a negative answer to an open problem of [M.…

Quantum Physics · Physics 2014-04-02 Nengkun Yu , Runyao Duan , Mingsheng Ying

The recognition of entanglement states is a notoriously difficult problem when no prior information is available. Here, we propose an efficient quantum adversarial bipartite entanglement detection scheme to address this issue. Our proposal…

The entanglement measure for multiqudits is proposed. This measure calculates the partial entanglement distributed by subsystems and the complete entanglement of the total system. This shows that we need to measure the subsystem…

Quantum Physics · Physics 2007-05-23 Hyuk-jae Lee , Sung Dahm Oh , Doyeol Ahn

We construct an important missing piece in the entanglement theory of pure three-qubit states, which is a polynomial measure of W-entanglement, working in parallel to the three-tangle, which is a polynomial measure of GHZ-entanglement, and…

Quantum Physics · Physics 2025-12-12 Szilárd Szalay

Entanglement is a key resource to demonstrate quantum advantage over classical strategies. Entanglement in quantum states is one of the most well-explored areas in quantum physics. However, a rigorous approach to understanding and detecting…

Quantum Physics · Physics 2025-02-12 Shubhayan Sarkar

We present general numerical methods to construct witness operators for entanglement detection and estimation of the fidelity. Our methods are applied to detecting entanglement in the vicinity of a six-qubit Dicke state with three…

We present a family of three-qubit quantum states with a basic local hidden variable model. Any von Neumann measurement can be described by a local model for these states. We show that some of these states are genuine three-partite…

Quantum Physics · Physics 2007-05-23 Geza Toth , Antonio Acin

The classification of the multipartite entanglement is an important problem in quantum information theory. We propose a class of two qubit mixed states $\sigma_{AB}=…

Quantum Physics · Physics 2014-08-08 Jyoti Faujdar , Anoopa Joshi , Satyabrata Adhikari

We study quantum states for which the PPT criterion is both sufficient and necessary for separability. We present a class of 3x3 bipartite mixed states and show that these states are separable if and only if they are PPT.

Quantum Physics · Physics 2009-05-01 Shao-Ming Fei , Xianqing Li-Jost

Sharing genuine multipartite entanglement by considering collective use of copies of biseparable states, which are entangled across all bipartitions but lack genuine multipartite entanglement at the single-copy level, plays a central role…

Quantum Physics · Physics 2026-01-26 Swati Choudhary , Ujjwal Sen , Saronath Halder

We show that entanglement of pure multi-party states can be quantified by means of quantum uncertainties of certain basic observables through the use of measure that has been initially proposed in [10] for bipartite systems.

Quantum Physics · Physics 2016-08-16 Alexander A. Klyachko , Barış Öztop , Alexander S. Shumovsky

The entanglement of assistance quantifies the amount of entanglement that can be concentrated among a group of spatially-separated parties using the assistance of some auxiliary system. In this paper we study the entanglement of assistance…

Quantum Physics · Physics 2023-10-11 Klée Pollock , Ge Wang , Eric Chitambar

A new method is developed to derive an algebraic equations for the geometric measure of entanglement of three qubit pure states. The equations are derived explicitly and solved in cases of most interest. These equations allow oneself to…

Quantum Physics · Physics 2008-03-01 Levon Tamaryan , DaeKil Park , Sayatnova Tamaryan

While the concept of entanglement for distinguishable particles is well established, defining entanglement and non-locality in systems of indistinguishable particles, which require the use of the (anti)symmetrization postulate, remains…

Quantum Physics · Physics 2025-04-10 P. Céspedes , F. H. Holik , A. P. Majtey

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…