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Two parts of an entangled quantum state can have a correlation in their joint behavior under measurements that is unexplainable by shared classical information. Such correlations are called non-local and have proven to be an interesting…

Quantum Physics · Physics 2009-03-25 Manuel Forster , Severin Winkler , Stefan Wolf

In this paper, we consider quantum correlations (quantum discord and local quantum uncertainty) in a vertical quantum dot. Their dependencies on magnetic field and temperature are presented in detail. It is noticeable that, quantum discord…

Quantum Physics · Physics 2014-01-21 E. Faizi , H. Eftekhari

Probes that measure the local thermal properties of systems out of equilibrium are emerging as new tools in the study of nanoscale systems. One can then measure the temperature of a probe that is weakly coupled to a bias-driven system. By…

Strongly Correlated Electrons · Physics 2015-05-13 LvZhou Ye , Dong Hou , Xiao Zheng , YiJing Yan , Massimiliano Di Ventra

By using geometric measure of discord (\texttt{GMOD})[Phys. Rev. Lett, 105, 109502 (2010)] and measurement-induced nonlocality (\texttt{MIN})[Phys. Rev. Lett, 106, 120401 (2011)], we investigate quantum correlation of a pair of two-level…

Quantum Physics · Physics 2015-06-03 Guo-Feng Zhang , Heng Fan , Ai-Ling Ji , Wu-Ming Liu

Equilibrium probes have been widely used in various noisy quantum metrology schemes. However, such an equilibrium-probe-based metrology scenario severely suffers from the low-temperature-error divergence problem in the weak-coupling regime.…

Quantum Physics · Physics 2025-05-28 Ze-Zhou Zhang , Hong-Gang Luo , Wei Wu

Quantum discord expresses a fundamental non-classicality of correlations more general than quantum entanglement. We combine the no-local-broadcasting theorem, semidefinite-programming characterizations of quantum fidelity and quantum…

Quantum Physics · Physics 2016-08-24 Marco Piani

Bell nonlocality, entanglement and nonclassical correlations are different aspects of quantum correlations for a given state. There are many methods to measure nonclassical correlations. In this paper, nonclassical correlations in two-qubit…

Quantum Physics · Physics 2015-05-28 Guo-Feng Zhang , Heng Fan , Ai-Ling Ji , Zhao-Tan Jiang , Ahmad Abliz , Wu-Ming Liu

Super-quantum discord is an extension of the quantum discord concept where weak measurements are made instead of projective measurements. We study the temperature behavior of the super-quantum discord for two real magnetic materials. We…

Quantum Physics · Physics 2019-10-07 A. V. Fedorova , T. Byrnes , A. N. Pyrkov

In quantum statistical mechanics, finite-temperature phase transitions are typically governed by classical field theories. In this context, the role of quantum correlations is unclear: recent contributions have shown how entanglement is…

Statistical Mechanics · Physics 2022-02-08 Poetri Sonya Tarabunga , Tiago Mendes-Santos , Fabrizio Illuminati , Marcello Dalmonte

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

The non-classical nature of quantum states, often illustrated using entanglement measures or quantum discord, constitutes a resource for quantum information protocols. However, the non-classicality of a quantum system cannot be encapsulated…

Quantum Physics · Physics 2016-02-18 Carole Addis , Teiko Heinosaari , Jukka Kiukas , Elsi-Mari Laine , Sabrina Maniscalco

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous-variable quantum entanglement and quantum discord for a system consisting of two…

Quantum Physics · Physics 2011-06-28 Aurelian Isar

The study of quantum information processing seeks to characterize the resources that enable quantum information processing to perform tasks that are unfeasible or inefficient for classical information processing. Quantum cryptography is one…

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

We review the main results and ideas showing that quantum correlations at finite temperatures (T), in particular quantum discord, are useful tools in characterizing quantum phase transitions that only occur, in principle, at the…

Quantum Physics · Physics 2012-12-24 T. Werlang , G. A. P. Ribeiro , Gustavo Rigolin

Resource identification and quantification is an essential element of both classical and quantum information theory. Entanglement is one of these resources, arising when quantum communication and nonlocal operations are expensive to…

Quantum Physics · Physics 2013-03-20 Sebastian Meznaric

It has been suggested that there may exist quantum correlations that go beyond entanglement. The existence of such correlations can be revealed by quantum discord, but not by the conventional measure of entanglement. We argue that a state…

Quantum Physics · Physics 2016-09-30 Pankaj Agrawal , Sk Sazim , Indranil Chakrabarty , Arun K. Pati

We employ the concepts of local quantum uncertainty and geometric quantum discord based on the trace norm to investigate the environmental effects on quantum correlations of two bipartite quantum systems. The first one concerns a two-qubit…

Quantum Physics · Physics 2019-04-10 Abdallah Slaoui , Mohammed Daoud , Rachid Ahl Laamara

Generalized measures of quantum correlations are derived by taking Bayes' rule as the only fundamental principle. The resulting quantifiers satisfy several desirable conditions for a measure of quantum correlations and are shown to admit…

Quantum Physics · Physics 2015-03-20 A. C. S. Costa , R. M. Angelo

We study the dynamics and the asymptotic behaviors of quantum discord in a one-dimensional XY model coupled through time-dependent nearest-neighbor interactions and in the presence of a time-dependent magnetic field. We find that the time…

Quantum Physics · Physics 2012-07-17 Jian Zhang , Bin Shao , Lian-Ao Wu , Jian Zou