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Related papers: Quantum correlations in spin models

200 papers

The discrepancy between maximally entangled states and maximally non-classical quantum correlations is well-known but still not well understood. We aim to investigate the relation between quantum correlations and entanglement in a family…

Quantum Physics · Physics 2016-03-01 Armin Tavakoli , Stefan Zohren , Marcin Pawlowski

The threshold between classical and nonclassical two-qubit states is drawn at the place when these states can no longer be described by classical correlations, i.e., quantum discord or entanglement appear. However, to check if the…

Quantum Physics · Physics 2013-06-05 Karol Bartkiewicz , Karel Lemr , Antonín Černoch , Jan Soubusta

We have investigated quantum phase transition employing the quantum renormalization group (QRG) method while in most previous literature barely entanglement (concurrence) has been demonstrated. However, it is now well known that…

Quantum Physics · Physics 2013-03-21 Yao Yao , Hong-Wei Li , Chun-Mei Zhang , Zhen-Qiang Yin , Guang-Can Guo , Zheng-Fu Han

In this paper we discuss various correlations measured by the concurrence (C), classical correlation (CC), quantum discord (QD), and geometric measure of discord (GMD) in a two-qubit Heisenberg XXZ spin chain in the presence of external…

Quantum Physics · Physics 2015-05-28 Jiang-Tao Cai , Ahmad Abliz , Shu-Shen Li

Generalized quantum discord $(D_q)$, Einstein-Podolsky-Rosen steering $(S)$, entanglement $(E)$, and Bell nonlocality ($N$), are logically distinct quantifiers of quantum correlations. All these measures capture nonclassical aspects of…

Quantum Physics · Physics 2016-04-07 A. C. S. Costa , M. W. Beims , R. M. Angelo

Bell's theorem states that, to simulate the correlations created by measurement on pure entangled quantum states, shared randomness is not enough: some "non-local" resources are required. It has been demonstrated recently that all…

Quantum Physics · Physics 2009-11-10 Nicolas Brunner , Nicolas Gisin , Valerio Scarani

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

In this article, we investigate the dynamics of a bipartite system under the action of a local non-Hermitian system. We study the quantum correlation of the bipartite system quantified by the entanglement, measurement-induced nonlocality…

Quantum Physics · Physics 2021-08-26 J. Ramya Parkavi , R. Muthuganesan , V. K. Chandrasekar

Measurement-induced nonlocality (MIN), a quantum correlation measure for the bipartite system, is an indicator of global effects due to locally invariant von Neumann projective measurements. It is well known fact that the correlation…

Quantum Physics · Physics 2020-07-02 R. Muthuganesan , V. K. Chandrasekar

The entanglement and quantum correlation measures have been investigated for the ground state of a spin chain with a Kitaev-type exchange interactions on alternating bonds, along with a transverse magnetic field. There is a macroscopic…

Quantum Physics · Physics 2018-11-14 Vimalesh Kumar Vimal , V. Subrahmanyam

In this work we propose a measure for the quantum discord of indistinguishable particles, based on the definition of entanglement of particles given in [H. M. Wiseman et al., Phis. Rev. Lett 91, 097902 (2003)]. This discord of particles is…

Quantum Physics · Physics 2016-04-28 Andrea Beggi , Fabrizio Buscemi , Paolo Bordone

We investigate the relation between quantum nonlocality and gravity at the astrophysical scale, both in the classical and quantum regimes. Considering particle pairs orbiting in the strong gravitational field of ultra-compact objects, we…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Luciano Petruzziello , Fabrizio Illuminati

Quantum entanglement and Bell nonlocality are two phenomena that occur only in quantum systems. In both cases, these are correlations between two subsystems that are classically absent. Traditionally, these phenomena have been measured in…

High Energy Physics - Phenomenology · Physics 2025-10-13 Tao Han , Matthew Low , Youle Su

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

We provide a novel criterion for identifying quantum correlation, which allows us to find connections between Bell type inequalities, entanglement detection, and correlation. We utilize the criterion to construct witness operators that can…

Quantum Physics · Physics 2007-05-23 Che-Ming Li , Li-Yi Hsu , Wei-Yang Lin , Yueh-Nan Chen , Der-San Chuu , Tobias Brandes

Entanglement of quasiclassical (coherent) states of two harmonic oscillators leads to striking quantum effects and is useful for quantum technologies. These effects and applications are closely related to nonlocal correlations inherent in…

Quantum Physics · Physics 2019-05-14 Zhi-Rong Zhong , Jian-Qi Sheng , Li-Hua Lin , Shi-Biao Zheng

By introducing a quantitative `degree of commutativity' in terms of the angle between spin-observables we present two tight quantitative trade-off relations in the case of two qubits: First, for entangled states, between the degree of…

Quantum Physics · Physics 2007-10-09 Michael Seevinck , Jos Uffink

We consider two particles of spin-1/2 interacting with a one-dimensional N-spin array, which is an exactly solvable model. The dynamics of entanglement and quantum discord (QD) of the spins of the two particles is investigated by regarding…

Quantum Physics · Physics 2015-08-27 Yan Liu , Jing Lu , Lan Zhou

We show that for two-qubit chained Bell inequalities with an arbitrary number of measurement settings, nonlocality and entanglement are not only different properties but are inversely related. Specifically, we analytically prove that in…

Quantum Physics · Physics 2014-01-08 G. Vallone , G. Lima , E. S. Gómez , G. Cañas , J. -A. Larsson , P. Mataloni , A. Cabello

We address the problem of detecting non-locality in coupled N level systems in the language of spin. Through a number of examples, we show that non-locality can be detected via a violation of the standard Bell inequality, irrespective of…

Quantum Physics · Physics 2015-09-08 V. Ravishankar , R. P. Sandhir