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Related papers: Oblique discord

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Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively…

Quantum Physics · Physics 2016-05-03 Yu Guo

Here, we show that partial transposition, which is initially introduced to study entanglement, can also inspire many results on quantum discord including: (I) a discord criterion of spectrum invariant under partial transposition, stating…

Quantum Physics · Physics 2023-05-17 Sun Liang-Liang , Zhou Xiang , Yu Sixia

Top quarks have been recently shown to be a promising system to study quantum information at the highest-energy scale available. The current lines of research mostly discuss topics such as entanglement, Bell nonlocality or quantum…

Quantum Physics · Physics 2023-06-07 Yoav Afik , Juan Ramón Muñoz de Nova

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 common use in literature of orthogonal measurements in obtaining quantum discord for two-qubit states is discussed and compared with more general measurements. We prove the optimality of orthogonal measurements for rank 2 states. While…

Quantum Physics · Physics 2012-02-01 Fernando Galve , Gianluca Giorgi , Roberta Zambrini

We extend the definition of quantum discord as a quantifier of nonClassical correlations in a quantum state to the case where weak measurements are performed on subsystem $A$ of a bipartite system $AB$. The properties of weak discord are…

Quantum Physics · Physics 2015-12-01 Lekshmi S , N Shaji , Anil Shaji

We propose a framework to characterize entanglement with quantum discord, both asymmetric and symmetric, over state extensions. In particular, we show that the minimal Bures distance of discord over state extensions is equivalent to Bures…

Quantum Physics · Physics 2022-01-27 Chunhe Xiong , Sunho Kim , Daowen Qiu , Asutosh Kumar , Junde Wu

Quantum discord, as introduced by Olliver and Zurek [Phys. Rev. Lett. \textbf{88}, 017901 (2001)], is a measure of the discrepancy between quantum versions of two classically equivalent expressions for mutual information and is found to be…

Quantum Physics · Physics 2015-06-04 Ali Saif M. Hassan , Pramod S. Joag

Quantum discord, a kind of quantum correlation based on entropic measures, is defined as the difference between quantum mutual information and classical correlation in a bipartite system. Procedures are available for analytical calculation…

Quantum Physics · Physics 2018-07-26 A. R. P. Rau

Quantum discord goes beyond entanglement and exists in a wide range of quantum states that may be separable, playing a crucial role in quantum information tasks. In this paper, we firstly proposed a zero-discord criterion for two-qubit…

Quantum Physics · Physics 2024-08-13 Wang Yiding , Huang Xiaofen , Zhang Tinggui

Entanglement distribution with separable states has recently attracted considerable attention. Recent results suggest that quantum discord - a measure for quantum correlations beyond entanglement - is responsible for this counterintuitive…

Quantum Physics · Physics 2014-09-26 Alexander Streltsov , Hermann Kampermann , Dagmar Bruß

Quantum discord is an important measure of quantum correlations that can serve as a resource for certain types of quantum information processing. \ Like entanglement, discord is subject to destruction by external noise. The routes by which…

Quantum Physics · Physics 2013-10-22 Nga T. T. Nguyen , Robert Joynt

Quantum entanglement is the most popular kind of quantum correlations, and its fundamental role in several tasks in quantum information theory like quantum cryptography, quantum dense coding, and quantum teleportation is undeniable.…

Quantum Physics · Physics 2014-11-13 Alexander Streltsov

Coherent interactions that generate negligible entanglement can still exhibit unique quantum behaviour. This observation has motivated a search beyond entanglement for a complete description of all quantum correlations. Quantum discord is a…

Quantum discord quantifies quantum correlation between quantum systems, which has potential application in quantum information processing. In this paper, we propose a scheme realizing the remote transfer of Gaussian quantum discord, in…

Quantum Physics · Physics 2023-07-19 Lingyu Ma , Xiaolong Su

In this brief review, we discuss the role that quantum correlations, as quantified by quantum discord, play in two interesting settings. The first one is discerning which unitaries have been applied on a quantum system, by taking advantage…

Quantum Physics · Physics 2017-08-01 Mile Gu , Stefano Pirandola

Quantum discord is an optimal resource for the quantification of classical and non-classical correlations as compared to other related measures. Geometric measure of quantum discord is another measure of quantum correlations. Recently, the…

Quantum Physics · Physics 2013-08-06 M. Ramzan

A measure of quantum correlation defined from an information-theoretic perspective, namely, quantum discord, is applied to study the time-evolved nonequilibrium state of the infinite anisotropic quantum XY spin chain in a transverse…

Quantum Physics · Physics 2012-06-20 Himadri Shekhar Dhar , Rupamanjari Ghosh , Aditi Sen De , Ujjwal Sen

We calculate the quantum discord between two free modes of a scalar field which start in a maximally entangled state and then undergo a relative, constant acceleration. In a regime where there is no distillable entanglement due to the Unruh…

Quantum Physics · Physics 2013-05-29 Animesh Datta

Local unitary operations allow for a unifying approach to the quantification of quantum correlations among the constituents of a bipartite quantum system. For pure states, the distance between a given state and its image under…

Quantum Physics · Physics 2015-10-23 M. Cianciaruso , S. M. Giampaolo , W. Roga , G. Zonzo , M. Blasone , F. Illuminati