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Related papers: Quantum discord in finite XY chains

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Quantum discord provides a measure for quantifying quantum correlations beyond entanglement and is very hard to compute even for two-qubit states because of the minimization over all possible measurements. Recently a simple algorithm to…

Quantum Physics · Physics 2011-10-10 Qing Chen , Chengjie Zhang , Sixia Yu , X. X. Yi , C. H. Oh

We study thermal quantum discord (TQD) in the Heisenberg chain with spin site or magnetic impurity. The former one of which may induce inhomogeneous exchange interactions between the neighboring spins, while the latter one modelling a spin…

Quantum Physics · Physics 2015-06-18 Jia-Min Gong , Zhan-Qiang Hui

The entanglement asymmetry is a novel quantity that, using entanglement methods, measures how much a symmetry is broken in a part of an extended quantum system. So far it has only been used to characterise the breaking of continuous Abelian…

Statistical Mechanics · Physics 2024-02-08 Florent Ferro , Filiberto Ares , Pasquale Calabrese

We consider the quantum discord in a two-particle spin-1/2 system (dimer) governed by the standard multiple quantum (MQ) Hamiltonian and reveal the relation between the discord and the intensity of the second-order MQ coherence. Since the…

Quantum Physics · Physics 2015-05-30 E. I. Kuznetsova , A. I. Zenchuk

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

Open quantum systems have attracted great attention, since inevitable coupling between quantum systems and their environment greatly affects the features of interest of these systems. Quantum discord, is a measure of the total nonclassical…

Quantum Physics · Physics 2012-11-30 Jin-Shi Xu , Chuan-Feng Li

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

In an initially uncorrelated mixed separable bi-partite system, quantum correlations can emerge under the action of a local measurement or local noise [A. Streltsov, H. Kampermann, and D. Bru\ss{}, Phys. Rev. Lett. 107, 170502 (2011)]. We…

Quantum Physics · Physics 2015-06-17 Richard Tatham , Natalia Korolkova

The key ingredient of the approach, presented in this paper, is the factorization property of $SU(2)$ coherent states upon splitting or decay of a quantum spin system. In this picture, the even and odd spin coherent states are viewed as…

Quantum Physics · Physics 2013-10-30 M. Daoud , R. Ahl Laamara , W. Kaydi

We study the pairwise quantum discord (QD) for a symmetric multi-qubit system in different types of noisy channels, such as phase-flip, amplitude damping, phase-damping, and depolarizing channels. Using the QD and geometric measure of…

Quantum Physics · Physics 2016-02-17 You-neng Guo , Mao-fa Fang , Zeng Ke , Guo-you Wang

We consider quantum correlations in a spin-1/2 open chain of $N$ nodes with the XY Hamiltonian using different bases for the density matrix representation and the initial state with a single polarized node. These bases of our choice are…

Quantum Physics · Physics 2015-06-05 E. B. Fel'dman , A. I. Zenchuk

The singularity of quantum correlations, such as quantum entanglement(QE) and quantum discord(QD), has been widely regarded as a valuable indicator for quantum phase transition(QPT) in low-dimensional quantum systems. In this paper, for a…

Quantum Physics · Physics 2013-07-25 H. L. Huang , Z. Y. Sun , B. Wang

Here, we compare the behavior of the quantum discord, 1-norm geometric quantum discord and concurrence under the effect of decoherence for XXX Heisenberg spin chain. Their dependencies on temperature and coupling constant are presented in…

Quantum Physics · Physics 2014-06-19 E. Faizi , H. Eftekhari

We consider the evaluation of the quantum discord and other related measures of quantum correlations in a system formed by a spin 1 and a complementary spin system. A characterization of general projective measurements in such system in…

Quantum Physics · Physics 2015-06-05 R. Rossignoli , J. M. Matera , N. Canosa

We compute the quantum correlation (quantum discord (QD)) and the entanglement (EoF) between nearest neighbor qubits (spin-1/2) in an infinite chain described by the Heisenberg model (XXZ Hamiltonian) at finite temperatures. The chain is in…

Quantum Physics · Physics 2015-05-19 T. Werlang , C. Trippe , G. A. P. Ribeiro , Gustavo Rigolin

We study the pairwise entanglement close to separable ground states of a class of one dimensional quantum spin models. At T=0 we find that such ground states separate regions, in the space of the Hamiltonian parameters, which are…

Statistical Mechanics · Physics 2009-11-11 L. Amico , F. Baroni , A. Fubini , D. Patane' , V. Tognetti , P. Verrucchi

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

We perform an experimental investigation of Quantum Discord with Spin-Orbit X-states. These states are prepared through the incoherent superposition of different laser beans, where a two-level system is encoded in polarization and the…

Quantum Physics · Physics 2023-12-29 V. S. Lamego , D. G. Braga , W. F. Balthazar , J. A. O. Huguenin

The study of low-dimensional metal complexes has revealed fascinating characteristics regarding the ground-state crossover shown by spin-gaped systems. In this context, this work explores the effect of the quantum-level crossing, induced by…

Quantum Physics · Physics 2023-07-05 Clebson Cruz , Maron F. Anka , Hamid-Reza Rastegar-Sedehi , Cleidson Castro

We use a disordered anti-ferromagnetic spin-1/2 chain with anisotropic exchange coupling to model an array of interacting qubits. All qubits have the same level spacing, except two, which are called the defects of the chain. The level…

Quantum Physics · Physics 2009-11-10 L. F. Santos , G. Rigolin