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Related papers: Coherence distribution in multipartite systems

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We investigate how quantum coherence can be distributed among the several off-diagonal elements of an arbitrary density matrix. An easily computable quantity that captures this variability notion is proposed and it is argued that it…

Quantum Physics · Physics 2026-04-24 Fernando Parisio

Based on the relative entropy, we give a unified characterization of quantum correlations for nonlocality, steerability, discord and entanglement for any bipartite quantum states. For two-qubit states we show that the quantities obtained…

Quantum Physics · Physics 2017-04-14 Tinggui Zhang , Hong Yang , Xianqing Li-Jost , Shao-Ming Fei

Quantum correlations between parts of a composite system most clearly reveal themselves through entanglement. Designing, maintaining, and controlling entangled systems is very demanding, which raises the stakes for understanding the…

Quantum Physics · Physics 2019-09-04 Matthew A. Hunt , Igor V. Lerner , Igor V. Yurkevich , Yuval Gefen

Quantum discord has been studied extensively as a measure of non-classical correlations which includes entanglement as a subset. Although it is well known that non-zero discord can exist without entanglement, the origin of quantum discord…

Quantum Physics · Physics 2017-08-02 Yu Guo , Sumit Goswami

Recent results in quantum information theory characterize quantum coherence in the context of resource theories. Here we study the relation between quantum coherence and quantum discord, a kind of quantum correlation which appears even in…

Quantum Physics · Physics 2016-04-29 Jiajun Ma , Benjamin Yadin , Davide Girolami , Vlatko Vedral , Mile Gu

Quantum coherence as an important quantum resource plays a key role in quantum theory. In this paper, using entropy-based measures, we investigate the relations between quantum correlated coherence, which is the coherence between subsystems…

Quantum Physics · Physics 2017-03-03 Xiao-Li Wang , Qiu-Ling Yue , Chao-Hua Yu , Fei Gao , Su-Juan Qin

Some new identities for quantum variance and covariance involving commutators are presented, in which the density matrix and the operators are treated symmetrically. A measure of entanglement is proposed for bipartite systems, based on…

Quantum Physics · Physics 2009-11-06 R I A Davis , R Delbourgo , P D Jarvis

The robustness of multipartite entanglement of systems undergoing decoherence is of central importance to the area of quantum information. Its characterization depends however on the measure used to quantify entanglement and on how one…

Quantum Physics · Physics 2015-05-20 Rafael Chaves , Luiz Davidovich

In relation of observable and quantum state, the entity $I_C$ from previous work quantifies simultaneously coherence, incompatibility and quantumness. In this article its application to quantum correlations in bipartite states is studied.…

Quantum Physics · Physics 2007-05-23 Fedor Herbut

Quantum correlation includes quantum entanglement and quantum discord. Both entanglement and discord have a common necessary condition--------quantum coherence or quantum superposition. In this paper, we attempt to give an alternative…

Quantum Physics · Physics 2014-09-23 Chang-shui Yu , Yang Zhang , Haiqing Zhao

A generalization of quantum discord to multipartite systems is proposed. A key feature of our formulation is its consistency with the conventional definition of discord in bipartite systems. It is by construction zero only for systems with…

Quantum Physics · Physics 2020-03-25 Chandrashekar Radhakrishnan , Mathieu Lauriere , Tim Byrnes

The quantum discord is used as measure of quantum correlations for two families of multipartite coherent states. The first family interpolates between generalized GHZ states and generalized Werner states. The second one is an interpolation…

Quantum Physics · Physics 2012-11-01 M. Daoud , R. Ahl Laamara

Quantum correlations between parts of a composite system most clearly reveal themselves through entanglement. Designing, maintaining, and controlling entangled systems is very demanding, which raises the stakes for understanding the…

Quantum Physics · Physics 2019-08-21 Matthew A. Hunt , Igor V. Lerner , Igor V. Yurkevich , Yuval Gefen

The total correlations in a bipartite quantum system are measured by the quantum mutual information $\mathcal{I}$, which consists of quantum discord and classical correlation. However, recent results in quantum information shows that…

Quantum Physics · Physics 2017-10-25 Jin-Xing Hou , Si-Yuan Liu , Xiao-Hui Wang , Wen-Li Yang

The definition of accessible coherence is proposed. Through local measurement on the other subsystem and one way classical communication, a subsystem can access more coherence than the coherence of its density matrix. Based on the local…

Quantum Physics · Physics 2017-04-27 Teng Ma , Ming-Jing Zhao , Hai-Jun Zhang , Shao-Ming Fei , Gui-Lu Long

The quantum discord of bipartite systems is one of the best-known measures of non-classical correlations and an important quantum resource. In the recent work appeared in [Phys. Rev. Lett 2020, 124:110401], the quantum discord has been…

Quantum Physics · Physics 2022-05-16 Jianming Zhou , Xiaoli Hu , Naihuan Jing

We study the entanglement dynamics of two qubits, each of which is embedded into its local amplitude-damping reservoir, and the entanglement distribution among all the bipartite subsystems including qubit-qubit, qubit-reservoir, and…

Quantum Physics · Physics 2011-08-26 Qing-Jun Tong , Jun-Hong An , Hong-Gang Luo , C. H. Oh

Both coherence and entanglement stem from the superposition principle, capture quantumness of a physical system, and play a central role in quantum physics. In a multipartite quantum system, coherence and quantum correlations are closely…

Quantum Physics · Physics 2018-08-08 Sunho Kim , Longsuo Li , Asutosh Kumar , Junde Wu

A new measure based on the tripartite information diagram is proposed for identifying quantum discord in tripartite systems. The proposed measure generalizes the mutual information underlying discord from bipartite to tripartite systems,…

Quantum Physics · Physics 2017-11-15 Wei-Ting Lee , Che-Ming Li

Quantum coherence and distributed correlations among subparties are often considered as separate, although operationally linked to each other, properties of a quantum state. Here, we propose a measure able to quantify the contributions…

Quantum Physics · Physics 2018-12-11 Gian Luca Giorgi , Roberta Zambrini