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Related papers: Bipartite concurrence and localized coherence

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Purity and coherence of a quantum state are recognized as useful resources for various information processing tasks. In this article, we propose a fidelity based valid measure of purity and coherence monotone and establish a relationship…

Quantum Physics · Physics 2021-04-09 Indrajith V S , R. Muthuganesan , R. Sankaranarayanan

It is well known that random bipartite pure states are typically maximally entangled within an arbitrarily small error. Showing that the marginals of random bipartite pure states are typically extremely close to the maximally mixed state,…

Quantum Physics · Physics 2016-04-21 Kaifeng Bu , Uttam Singh , Lin Zhang , Junde Wu

Some features of the global entanglement of a composed quantum system can be quantified in terms of the purity of a balanced bipartition, made up of half of its subsystems. For the given bipartition, purity can always be minimized by taking…

Quantum Physics · Physics 2011-05-10 P. Facchi , G. Florio , U. Marzolino , G. Parisi , S. Pascazio

We focus our attention on tripartite mixed states as initial states, and apply coherence concurrence to investigate quantum coherence properties in the background of a Schwarzschild black hole under phase damping, phase flip and bit flip…

Quantum Physics · Physics 2026-02-25 Tangrui Liao , Junhao Yang , Tinggui Zhang , Xiaofen Huang

We introduce a quantity called the coherence of purification which can be a measure of total quantumness for a single system. We prove that coherence of purification is always more than the coherence of the system. For a pure state, the…

Quantum Physics · Physics 2019-07-31 Arun Kumar Pati , Long-Mei Yang , Chiranjib Mukhopadhyay , Shao-Ming Fei , Zhi-Xi Wang

We introduce a complete set of complementary quantities in bipartite, two-dimensional systems. Complementarity then relates the quantitative entanglement measure concurrence which is a bipartite property to the single-particle quantum…

Quantum Physics · Physics 2007-05-23 Matthias Jakob , Janos A. Bergou

The Schmidt coefficients capture all entanglement properties of a pure bipartite state and therefore determine its usefulness for quantum information processing. While the quantification of the corresponding properties in mixed states is…

Quantum Physics · Physics 2019-04-08 Gael Sentís , Christopher Eltschka , Otfried Gühne , Marcus Huber , Jens Siewert

Multipartite quantum states that cannot be uniquely determined by their reduced states of all proper subsets of the parties exhibit some inherit `high-order' correlation. This paper elaborates this issue by giving necessary and sufficient…

Quantum Physics · Physics 2008-08-29 Yuan Feng , Runyao Duan , Mingsheng Ying

We study the concurrence of arbitrary dimensional bipartite quantum systems. By using a positive but not completely positive map, we present an analytical lower bound of concurrence. Detailed examples are used to show that our bound can…

Quantum Physics · Physics 2014-01-09 Hui-hui Qin , Shao-Ming Fei

This paper studies the quantification and structural properties of quantum average correlation based on average coherence. Motivated by two mathematically equivalent approaches to define average coherence: one by averaging over complete…

Quantum Physics · Physics 2026-04-28 Xiaoyu Ma , Qing-Hua Zhang , Cong Xu

Coherence is a fundamental notion in quantum mechanics, defined relative to a reference basis. As such, it does not necessarily reveal the locality of interactions nor takes into account the accessible operations in a composite quantum…

Quantum Physics · Physics 2021-03-10 Alioscia Hamma , Georgios Styliaris , Paolo Zanardi

A fundamental task in any physical theory is to quantify certain physical quantity in a meaningful way. In this paper we show that both fidelity distance and affinity distance satisfy the strong contractibility, and the corresponding…

Quantum Physics · Physics 2019-03-05 Chunhe Xiong , Asutosh Kumar , Minyi Huang , Sreetama Das , Ujjwal Sen , Junde Wu

Quantum coherence is important in quantum mechanics, and its essence is from superposition principle. We study the coherence of any two pure states and that of their arbitrary superposition, and obtain the relationship between them. In the…

Quantum Physics · Physics 2016-05-25 Qiu-Ling Yue , Chao-Hua Yu , Feng Liu , Xiao-Li Wang , Fei Gao , Qiao-Yan Wen

For a tripartite pure state superposed by two individual states, the bipartitely shared entanglement can always be achieved by local measurements of the third party. Consider the different aims of the third party, i.e. maximizing or…

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

We study the entanglement of a multipartite quantum state. An inequality between the bipartite concurrence and the multipartite concurrence is obtained. More effective lower and upper bounds of the multipartite concurrence are obtained. By…

Quantum Physics · Physics 2015-05-19 Ming Li , Shao-Ming Fei , Zhi-Xi Wang

Quantum resources play crucial roles for displaying superiority in many quantum communication and computation tasks. To reveal the intrinsic relations hidden in these quantum resources, many efforts have been made in recent years. In this…

Quantum Physics · Physics 2019-03-27 Wen-Yang Sun , Dong Wang , Bao-Long Fang , Zhi-Yong Ding , Huan Yang , Fei Ming , Liu Ye

We show that two related measures of k-coherence, called the standard and generalized robustness of k-coherence, are equal to each other when restricted to pure states. As a direct application of the result, we establish an equivalence…

Quantum Physics · Physics 2018-08-29 Nathaniel Johnston , Chi-Kwong Li , Sarah Plosker , Yiu-Tung Poon , Bartosz Regula

We study the entanglement of tripartite quantum states and provide analytical lower bound of concurrence in terms of the concurrence of sub-states. The lower bound may improve all the existing lower bounds of concurrence. The approach is…

Quantum Physics · Physics 2012-08-09 Xue-Na Zhu , Ming-Jing Zhao , Shao-Ming Fei

The state of an atom in a bipartite qubit, Jaynes-Cummings (JC) or anti-Jaynes-Cummings (aJC) interaction is described by a reduced density operator. The purity of the state has been measured by taking the trace of the square of the reduced…

Quantum Physics · Physics 2022-07-07 Joseph Akeyo Omolo

A simplified expression of concurrence for two-qubit mixed state having no more than three non-vanishing eigenvalues is obtained. Basing on SU(2) coherent states, the amount of entanglement of two-qubit pure states is studied and conditions…

Quantum Physics · Physics 2012-04-06 S. Salimi , A. Mohammadzade , K. Berrada