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Related papers: X-arability of mixed quantum states

200 papers

We present a new approach to the analysis of entanglement in smooth bipartite continuous-variable states. One or both parties perform projective filterings via preliminary measurements to determine whether the system is located in some…

Quantum Physics · Physics 2009-11-13 H. -C. Lin , A. J. Fisher

The notions of $k$-separability and $k$-producibility are useful and expressive tools for the characterization of entanglement in multipartite quantum systems, when a more detailed analysis would be infeasible or simply needless. In this…

Quantum Physics · Physics 2021-03-05 Szilárd Szalay

In the quest of completely describing entanglement in the general case of a finite number of parties sharing a physical system of finite dimensional Hilbert space a new entanglement magnitude is introduced for its pure and mixed states:…

Quantum Physics · Physics 2009-10-31 Guifre Vidal , Rolf Tarrach

We consider the separability of rank two quantum states on multiple quantum spaces with different dimensions. The sufficient and necessary conditions for separability of these multiparty quantum states are explicitly presented. A…

Quantum Physics · Physics 2007-05-23 Shao-Ming Fei , Xiu-Hong Gao , Xiao-Hong Wang , Zhi-Xi Wang , Ke Wu

We provide a canonical form of mixed states in bipartite quantum systems in terms of a convex combination of a separable state and a, so-called, edge state. We construct entanglement witnesses for all edge states. We present a canonical…

Quantum Physics · Physics 2009-11-06 M. Lewenstein , B. Kraus , P. Horodecki , J. I. Cirac

Entanglement is a fundamental feature of quantum mechanics, playing a crucial role in quantum information processing. However, classifying entangled states, particularly in the mixed-state regime, remains a challenging problem, especially…

We consider an infinite spin chain as a bipartite system consisting of the left and right half-chain and analyze entanglement properties of pure states with respect to this splitting. In this context we show that the amount of entanglement…

Mathematical Physics · Physics 2009-11-11 M. Keyl , T. Matsui , D. Schlingemann , R. F. Werner

Although entanglement is both a central ingredient in our understanding of quantum many-body systems and an essential resource for quantum technologies, we only have a limited ability to quantify entanglement in real quantum materials. Thus…

We address the question of whether or not global entanglement of a quantum state can be inferred from local properties. Specifically, we are interested in genuinely multiparticle entangled states whose two-body marginals are all separable,…

Quantum Physics · Physics 2018-12-05 Marius Paraschiv , Nikolai Miklin , Tobias Moroder , Otfried Gühne

Reliable methods for the classification and quantification of quantum entanglement are fundamental to understanding its exploitation in quantum technologies. One such method, known as Separable Neural Network Quantum States (SNNS), employs…

Quantum Physics · Physics 2021-06-15 Cillian Harney , Mauro Paternostro , Stefano Pirandola

Clarifying the relation between the whole and its parts is crucial for many problems in science. In quantum mechanics, this question manifests itself in the quantum marginal problem, which asks whether there is a global pure quantum state…

Quantum Physics · Physics 2021-02-18 Xiao-Dong Yu , Timo Simnacher , Nikolai Wyderka , H. Chau Nguyen , Otfried Gühne

This article delves into an analysis of the intrinsic entanglement and separability feature in quantum states as depicted by graph Laplacian. We show that the presence or absence of edges in the graph plays a pivotal role in defining the…

Quantum Physics · Physics 2024-01-05 Anoopa Joshi , Parvinder Singh , Atul Kumar

The complicated ways in which electrons interact in many-body systems such as molecules and materials have long been viewed through the lens of local electron correlation and associated correlation functions. However, quantum information…

Strongly Correlated Electrons · Physics 2024-10-15 Tong Shen , Hatem Barghathi , Adrian Del Maestro , Brenda Rubenstein

In general the calculation of robustness of entanglement for the mixed entangled quantum states is rather difficult to handle analytically. Using the the convex semi-definite programming method, the robustness of entanglement of some mixed…

Quantum Physics · Physics 2016-09-08 M. A. Jafarizadeh , M. Mirzaee , M. Rezaee

We present a method to quantify quantum correlations in arbitrary systems of indistinguishable fermions using witness operators. The method associates the problem of finding the optimal entan- glement witness of a state with a class of…

Quantum Physics · Physics 2013-02-22 Fernando Iemini , Thiago O. Maciel , Tiago Debarba , Reinaldo O. Vianna

In recent years considerable progress has been made towards developing a general theory of quantum entanglement. In particular, criteria to decide whether a given quantum state is entangled are of high theoretical and practical interest.…

Quantum Physics · Physics 2025-01-27 Shruti Aggarwal

We show how an unknown mixed quantum state's entanglement can be quantified by a suitable, local parity measurement on its two-fold copy.

Quantum Physics · Physics 2015-06-26 Florian Mintert , Andreas Buchleitner

We investigate some basic scenarios in which a given set of bipartite quantum states may consistently arise as the set of reduced states of a global N-partite quantum state. Intuitively, we say that the multipartite state "joins" the…

Quantum Physics · Physics 2013-09-30 Peter D. Johnson , Lorenza Viola

A general and computable criterion for k-(in)separability in continuous multipartite quantum systems is presented. The criterion can be experimentally implemented with a finite and comparatively low number of local observables. We discuss…

Quantum Physics · Physics 2012-02-07 Andreas Gabriel , Marcus Huber , Sasa Radic , Beatrix C. Hiesmayr

We present a survey on mathematical topics relating to separable states and entanglement witnesses. The convex cone duality between separable states and entanglement witnesses is discussed and later generalized to other families of…

Quantum Physics · Physics 2011-01-24 Lukasz Skowronek