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Related papers: Lower Bound of Concurrence Based on Positive Maps

200 papers

A simple relation is introduced for concurrence to describe how much the entanglement of bipartite system is at least left if either (or both) subsystem undergoes an arbitrary physical process. This provides a lower bound for concurrence of…

Quantum Physics · Physics 2009-11-13 Chang-shui Yu , X X Yi , He-shan Song

We provide a class of lower bounds for concurrence based on symmetric measurements. We show that our lower bounds estimate the quantum entanglement better than some existing lower bounds by detailed examples. Moreover, our lower bounds can…

Quantum Physics · Physics 2025-03-28 Hao-Fan Wang , Shao-Ming Fei

We obtain an analytical lower bound of entanglement quantified by concurrence for arbitrary bipartite quantum states. It is shown that our bound is tight for some mixed states and is complementary to the previous known lower bounds. On the…

Quantum Physics · Physics 2009-01-24 Yong-Cheng Ou , Heng Fan , Shao-Ming Fei

We propose a family of lower bounds for concurrence in quantum systems using mutually unbiased measurements, which prove more effective in entanglement estimation compared to existing methods. Through analytical and numerical examples, we…

Quantum Physics · Physics 2025-04-22 Yu Lu , Meng Su , Zhong-Xi Shen , Hong-Xing Wu , Shao-Ming Fei , Zhi-Xi Wang

Quantum entanglement plays a pivotal role in quantum information processing. Quantifying quantum entanglement is a challenging and essential research area within the field. This manuscript explores the relationships between bipartite…

Quantum Physics · Physics 2025-04-22 Ming Li , Yaru Dong , Ruiqi Zhang , Xuena Zhu , Shuqian Shen , Lei Li , Shao-Ming Fei

We derive an analytical lower bound for the concurrence of tripartite quantum mixed states. A functional relation is established relating concurrence and the generalized partial transpositions.

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

We obtain analytical lower bounds on the concurrence of bipartite quantum systems in arbitrary dimensions related to the violation of separability conditions based on local uncertainty relations and on the Bloch representation of density…

Quantum Physics · Physics 2009-11-13 Julio I. de Vicente

We derive an analytical expression for the lower bound of the concurrence of mixed quantum states of composite 2xK systems. In contrast to other, implicitly defined entanglement measures, the numerical evaluation of our bound is…

Quantum Physics · Physics 2009-11-10 Artur Lozinski , Andreas Buchleitner , Karol Zyczkowski , Thomas Wellens

The detection and estimation of quantum entanglement are the essential issues in the theory of quantum entanglement. We construct matrices based on the realignment of density matrices and the vectorization of the reduced density matrices,…

Quantum Physics · Physics 2024-05-21 Jiaxin Sun , Hongmei Yao , Shao-Ming Fei , Zhaobing Fan

Employing a recently proposed separability criterion we develop analytical lower bounds for the concurrence and for the entanglement of formation of bipartite quantum systems. The separability criterion is based on a nondecomposable…

Quantum Physics · Physics 2007-05-23 Heinz-Peter Breuer

We derive an analytic approximation for the concurrence of weakly mixed bipartite quantum states - typical objects in state of the art experiments. This approximation is shown to be a lower bound of the concurrence of arbitrary states.

Quantum Physics · Physics 2009-11-10 Florian Mintert , Andreas Buchleitner

The problems of genuine multipartite entanglement detection and classification are challenging. We show that a multipartite quantum state is genuine multipartite entangled if the multipartite concurrence is larger than certain quantities…

Quantum Physics · Physics 2015-12-31 Ming Li , Shao-Ming Fei , Xianqing Li-Jost , Heng Fan

We derive measurable lower bounds on concurrence of arbitrary mixed states, for both bipartite and multipartite cases. First, we construct measurable lower bonds on the purely algebraic bounds of concurrence [F. Mintert et al. (2004), Phys.…

Quantum Physics · Physics 2011-01-21 Iman Sargolzahi , Sayyed Yahya Mirafzali , Mohsen Sarbishaei

We present an analytical lower bound of multipartite concurrence based on the generalized Bloch representations of density matrices. It is shown that the lower bound can be used as an effective entanglement witness of genuine multipartite…

Quantum Physics · Physics 2016-08-05 Jing Wang , Ming Li , Hongfang Li , Shao-Ming Fei , Xianqing Li-Jost

We derive an explicit analytic estimate for the entanglement of a large class of bipartite quantum states which extends into bound entanglement regions. This is done by using an efficiently computable concurrence lower bound, which is…

We provide analytical lower and upper bounds for entanglement of formation for bipartite systems, which give a direct relation between the bounds of entanglement of formation and concurrence, and improve the previous results. Detailed…

Quantum Physics · Physics 2012-11-05 Xue-Na Zhu , Shao-Ming Fei

We provide a class of positive and trace-preserving maps based on symmetric measurements. From these positive maps we present separability criteria, entanglement witnesses, as well as the lower bounds of concurrence. We show by detailed…

Quantum Physics · Physics 2024-05-21 Jiaxin Li , Hongmei Yao , Shao-Ming Fei , Zhaobing Fan , Haitao Ma

In this paper we use the \textit{concurrence vector}, as a measure of entanglement, and investigate lower and upper bounds on the concurrence of a superposition of bipartite states as a function of the concurrence of the superposed states.…

Quantum Physics · Physics 2016-04-19 Seyed Javad Akhtarshenas

We argue that a complete characterisation of quantum correlations in bipartite systems of many dimensions may require a quantity which, even for pure states, does not reduce to a single number. Subsequently, we introduce multi-dimensional…

Quantum Physics · Physics 2009-11-07 Piotr Badziag , Piotr Deuar , Michal Horodecki , Pawel Horodecki , Ryszard Horodecki

To quantify the entanglement of bipartite systems in terms of some entanglement measure is a challenging problem in general, and it is much worse when the information about the system is less. In this manuscript, based on two classes of…

Quantum Physics · Physics 2024-01-01 Xian Shi