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Related papers: Generalizations of Quantum Discord

200 papers

Dakic, Vedral and Brukner [Physical Review Letters \tf{105},190502 (2010)] gave a geometric measure of quantum discord in a bipartite quantum state as the distance of the state from the closest classical quantum (or zero discord) state and…

Quantum Physics · Physics 2015-05-20 Ali Saif M. Hassan , Behzad Lari , Pramod S. Joag

Due to some ambiguity in defining mutual Tsallis entropy in the classical probability theory, its generalization to quantum theory is discussed and, as a consequence, two types of generalized quantum discord, called $q$-discords, are…

Quantum Physics · Physics 2012-06-04 Jacek Jurkowski

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

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

We propose a new criterion to judge zero quantum discord for arbitrary bipartite states. A bipartite quantum state has zero quantum discord if and only if all blocks of its density matrix are normal matrices and commute with each other.…

Quantum Physics · Physics 2015-03-19 Jie-Hui Huang , Lei Wang , Shi-Yao Zhu

The concept of quantum discord aims at unveiling quantum correlations that go beyond those described by entanglement. Its original formulation [J. Phys. A 34, 6899 (2001); Phys. Rev. Lett 88, 017901 (2002)] is difficult to compute even for…

Quantum discord quantifies non-classical correlations going beyond the standard classification of quantum states into entangled and unentangled ones. Although it has received considerable attention, it still lacks any precise interpretation…

Quantum Physics · Physics 2011-04-04 D. Cavalcanti , L. Aolita , S. Boixo , K. Modi , M. Piani , A. Winter

We extend the quantum discord to continuous variable systems and evaluate Gaussian quantum discord C(\rho) for bipartite Gaussian states. In particular, for squeezed thermal states (STS), we explicitly maximize the extractable information…

Quantum Physics · Physics 2015-05-18 Paolo Giorda , Matteo G. A. Paris

We propose a global measure for quantum correlations in multipartite systems, which is obtained by suitably recasting the quantum discord in terms of relative entropy and local von Neumann measurements. The measure is symmetric with respect…

Quantum Physics · Physics 2011-11-28 C. C. Rulli , M. S. Sarandy

Quantum discord is a measure of the quantumness of correlations. After reviewing its different versions and properties, we apply it to the questions of quantum information processing. First we show that changes in discord in the processed…

Quantum Physics · Physics 2015-03-17 Aharon Brodutch , Alexei Gilchrist , Daniel R. Terno , Christopher J. Wood

We investigate and compare three distinguished geometric measures of bipartite quantum correlations that have been recently introduced in the literature: the geometric discord, the measurement-induced geometric discord, and the discord of…

Quantum Physics · Physics 2016-05-26 Wojciech Roga , Dominique Spehner , Fabrizio Illuminati

Quantum discord represents a correlation beyond classicality that could be useful for many quantum information tasks, and therefore is viewed as a valuable quantum resource. Theoretically, whether a bipartite quantum state has a non-zero…

Quantum Physics · Physics 2025-06-10 Rong Wang , Yao Yao , Zhen-Qiang Yin

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

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

Originally introduced as the difference between two possible forms of quantum mutual information, quantum discord has posteriorly been shown to admit a formulation according to which it measures a distance between the state under scrutiny…

Quantum Physics · Physics 2018-10-01 P. R. Dieguez , R. M. Angelo

We investigate quantum states that posses both maximum entanglement and maximum discord between the pertinent parties. Since entanglement (discord) is defined only for bipartite (two qubit) systems, we shall introduce an appropriate sum…

Quantum Physics · Physics 2013-03-27 J. Batle , M. Casas , A. Plastino

Quantum discord (QD) reveals the nonclassical nature of correlations in bipartite quantum states, going beyond the entanglement-separability paradigm. In this article we discuss the suitability of QD in what concern its possible asymmetry…

Quantum Physics · Physics 2015-03-14 J. Maziero , L. C. Celeri , R. M. Serra

This paper summarizes the basics of the notion of quantum discord and how it relates to other types of correlations in quantum physics. We take the fundamental information theoretic approach and illustrate our exposition with a number of…

Quantum Physics · Physics 2017-02-07 Vlatko Vedral

We define a new measure of quantum correlations in bipartite quantum systems given by the Bures distance of the system state to the set of classical states with respect to one subsystem, that is, to the states with zero quantum discord. Our…

Quantum Physics · Physics 2013-12-23 Dominique Spehner , Miguel Orszag

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