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Related papers: Hierarchy of Separability Conditions for Bipartite…

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A group of symmetric operators are introduced to carry out the separability criterion for bipartite and multipartite quantum states. Every symmetric operator, represented by a symmetric matrix with only two nonzero elements, and their…

Quantum Physics · Physics 2012-12-04 Jie-Hui Huang , Li-Yun Hu , Lei Wang , Shi-Yao Zhu

Starting with a set of conditions for bipartite separability of arbitrary quantum states in any dimension and expressed in terms of arbitrary operators whose commutator is a $c$-number, we derive a hierarchy of conditions for tripartite…

Quantum Physics · Physics 2015-06-18 E. Shchukin , P. van Loock

Explicit sufficient and necessary conditions for separability of higher dimensional quantum systems with rank two density matrices are given. A nonseparability inequality is also presented, for the case where one of the eigenvectors…

Quantum Physics · Physics 2009-11-07 Sergio Albeverio , Shao-Ming Fei , Debashish Goswami

By combining a parameterized Hermitian matrix, the realignment matrix of the bipartite density matrix $\rho$ and the vectorization of its reduced density matrices, we present a family of separability criteria, which are stronger than the…

Quantum Physics · Physics 2015-11-03 Shu-Qian Shen , Meng-Yuan Wang , Ming Li , Shao-Ming Fei

We provide necessary and sufficient conditions for separability of mixed states. As a result we obtain a simple criterion of separability for $2\times2$ and $2\times3$ systems. Here, the positivity of the partial transposition of a state is…

Quantum Physics · Physics 2009-10-30 Michal Horodecki , Pawel Horodecki , Ryszard Horodecki

We derive a hierarchy of separability criteria for multi-mode continuous variable systems. They permit to study in a unified way the k-partite entanglement of broad classes of Gaussian and non- Gaussian states. With specific examples we…

Quantum Physics · Physics 2014-11-25 Antonio A. Valido , Federico Levi , Florian Mintert

Recently, a new and powerful separability criterion was introduced in [O. Rudolph, quant-ph/0202121] and [Chen {\it et al.}, quant-ph/0205017]. Composing the main idea behind the above criterion and the necessary and sufficient condition in…

Quantum Physics · Physics 2007-05-23 Michal Horodecki , Pawel Horodecki , Ryszard Horodecki

We study the norms of the Bloch vectors for arbitrary $n$-partite quantum states. A tight upper bound of the norms is derived for $n$-partite systems with different individual dimensions. These upper bounds are used to deal with the…

Quantum Physics · Physics 2020-08-07 Wen Xu , Chuan-Jie Zhu , Zhu-Jun Zheng , Shao-Ming Fei

We present an inequality that classifies mixed multipartite systems of an arbitrary dimension with respect to separability and positivity of partial transpose properties. This inequality gives a way to experimentally classify the observed…

Quantum Physics · Physics 2009-11-11 Koji Nagata

We provide a class of inequalities for detecting entanglements in multi-mode systems. Necessary conditions for fully separable, bi-separable and sufficient conditions for fully entangled states are explicitly presented.

Quantum Physics · Physics 2007-05-23 Zong-Guo Li , Shao-Ming Fei , Zhi-Xi Wang , Ke Wu

We study bipartite entanglement in systems of N identical bosons distributed in M different modes. For such systems, a definition of separability not related to any a priori Hilbert space tensor product structure is needed and can be given…

Quantum Physics · Physics 2012-03-15 F. Benatti , R. Floreanini , U. Marzolino

A density operator of a bipartite quantum system is called robustly separable if it has a neighborhood of separable operators. Given a bipartite density matrix, its property to be robustly separable is reduced, using the continuous ensemble…

Quantum Physics · Physics 2007-05-23 Roman R. Zapatrin

We study separability criteria in multipartite quantum systems of arbitrary dimensions by using the Bloch representation of density matrices. We first derive the norms of the correlation tensors and obtain the necessary conditions for…

Quantum Physics · Physics 2020-09-08 Hui Zhao , Mei-Ming Zhang , Naihuan Jing , Zhi-Xi Wang

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

The principle of local distinguishability states that an arbitrary physical state of a bipartite system can be determined by the combined statistics of local measurements performed on the subsystems. A necessary and sufficient requirement…

Quantum Physics · Physics 2015-05-15 Claudio Carmeli , Teiko Heinosaari , Jussi Schultz , Alessandro Toigo

Explicit sufficient and necessary conditions for separability of $N$-dimensional rank two multiparty quantum mixed states are presented. A nonseparability inequality is also given, for the case where one of the eigenvectors corresponding to…

Quantum Physics · Physics 2015-06-26 Shao-Ming Fei , Xiu-Hong Gao , Xiao-Hong Wang , Zhi-Xi Wang , Ke Wu

We provide necessary and sufficient conditions for the partial transposition of bipartite harmonic quantum states to be nonnegative. The conditions are formulated as an infinite series of inequalities for the moments of the state under…

Quantum Physics · Physics 2009-11-11 E. Shchukin , W. Vogel

We study the separability of bipartite quantum systems in arbitrary dimensions based on the Bloch representation of density matrices. We present two separability criteria for quantum states in terms of the matrices $T_{\alpha\beta}(\rho)$…

Quantum Physics · Physics 2023-05-11 Xue-Na Zhu , Jing Wang , Gui Bao , Ming Li , Shu-Qian Shen , Shao-Ming Fei

In this paper, we present the necessary and sufficient conditions of separability for bipartite pure states in infinite dimensional Hilbert spaces. Let $M$ be the matrix of the amplitudes of $\ket\psi$, we prove $M$ is a compact operator.…

Quantum Physics · Physics 2007-05-23 Su Hu , Zongwen Yu

We study the distillability of a certain class of bipartite density operators which can be obtained via depolarization starting from an arbitrary one. Our results suggest that non-positivity of the partial transpose of a density operator is…

Quantum Physics · Physics 2009-10-31 W. Dür , J. I. Cirac , M. Lewenstein , D. Bruss