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Related papers: Nullity of quantum discord of two-qubit X-state sy…

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We study and compare the time evolutions of concurrence and quantum discord in a driven system of two interacting qubits prepared in a generic Werner state. The~corresponding quantum dynamics is exactly treated and manifests the appearance…

Quantum Physics · Physics 2020-10-09 Iulia Ghiu , Roberto Grimaudo , Tatiana Mihaescu , Aurelian Isar , Antonino Messina

The decoherence of quantum correlation is investigated in the Heisenberg spin system with the asymmetric anisotropic interactions. The quantum entanglement and discord are used to quantify the quantumness of the correlations. By the…

Quantum Physics · Physics 2012-08-09 Xiang Hao , Chunlan Ma , Jinqiao Sha

We review recent studies on the measures of zero temperature quantum correlations namely, the quantum entanglement (concurrence) and discord present in the final state of a transverse XY spin chain following a quench through quantum…

Quantum Physics · Physics 2015-06-05 Tanay Nag , Amit Dutta , Ayoti Patra

We investigate the dissipative dynamics of quantum discord in a decoherence model with two initially entangled qubits in addition to a quantum kicked top. The two qubits are uncoupled during the period of our study and one of them interacts…

Quantum Physics · Physics 2015-05-20 Y. Y. Xu , W. L. Yang , M. Feng

We investigate the disappearance of discord in 2- and multi-qubit systems subject to decohering influences. We formulate the computation of quantum discord in terms of the generalized Bloch vector, which gives useful insights on the time…

Quantum Physics · Physics 2014-04-21 Hyungjun Lim , Robert Joynt

We analyse under which dynamical conditions the coherence of an open quantum system is totally unaffected by noise. For a single qubit, specific measures of coherence are found to freeze under different conditions, with no general agreement…

Quantum Physics · Physics 2015-05-28 Thomas R. Bromley , Marco Cianciaruso , Gerardo Adesso

We study bipartite quantum discord as a manifestation of a multipartite entanglement structure in the tripartite purified system. In particular, we find that bipartite quantum discord necessarily manifests itself in the presence of both…

Quantum Physics · Physics 2013-07-29 Eric G. Brown , Eric J. Webster , Eduardo Martin-Martinez , Achim Kempf

We evaluate analytically the quantum discord for a large family of multiqubit states. It is interesting to note that the quantum discord of three-qubits and five-qubits is the same, as is the quantum discord of two-qubits and six-qubits. We…

Quantum Physics · Physics 2021-08-04 Bo Li , Chen-Lu Zhu , Xiao-Bin Liang , Biao-Liang Ye , Shao-Ming Fei

Quantum discord is significant in analyzing quantum nonclassicality beyond the paradigm of entanglement. Presently we have explored the effectiveness of global unitary operations in manifesting quantum discord from a general two qubit zero…

Quantum Physics · Physics 2021-03-17 Kaushiki Mukherjee , Biswajit Paul , Sumana Karmakar

In quantum information theory, quantum discord has been proposed as a tool to characterise the presence of "quantum correlations" between the subparts of a given system. Whether a system behaves quantum-mechanically or classically is…

Quantum Physics · Physics 2022-10-20 Jerome Martin , Amaury Micheli , Vincent Vennin

We use quantum discord to characterize the correlations present in the quantum computational model DQC1, introduced by Knill and Laflamme [Phys. Rev. Lett. 81, 5672 (1998)]. The model involves a collection of qubits in the completely mixed…

Quantum Physics · Physics 2009-11-13 Animesh Datta , Anil Shaji , Carlton M. Caves

We analyze the roles of initial correlations between the two-qubit system and a dissipative cavity on quantum discord dynamics of two qubits. Considering two initial system-cavity states, we show that the initial system-cavity correlations…

Quantum Physics · Physics 2015-05-19 Ying-Jie Zhang , Xu-Bo Zou , Yun-Jie Xia

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

We introduce a simple and efficient technique to verify quantum discord in unknown Gaussian states and a certain class of non-Gaussian states. We show that any separation in the peaks of the marginal distributions of one subsystem…

We discuss the creation of quantum discord between two two-level atoms trapped in an optical cavity in a noisy environment. It is shown that nonzero steady-state quantum discord between atoms can be obtained when the white-noise field is…

Quantum Physics · Physics 2015-06-03 Jia-sen Jin , Chang-shui Yu , Pei Pei , He-shan Song

We have investigated the dynamics of quantum discord and entanglement for two qubits subject to independent global transverse and/or longitudinal memoryless noisy classical fields. Global transverse and/or longitudinal random fields are…

Quantum Physics · Physics 2012-11-28 Ferdi Altintas , Arzu Kurt , Resul Eryigit

We investigate the time evolution of negativity and quantum discord for a pair of non-interacting qubits with one being weakly coupled to a decohering Davies--type Markovian environment. At initial time of preparation, the qubits are…

Quantum Physics · Physics 2015-06-11 J. Dajka , M. Mierzejewski , J. Luczka , R. Blattmann , P. Hanggi

We analyze the quantum discord Q throughout the low-temperature phase diagram of the quantum XY model in transverse field. We first focus on the T=0 order-disorder quantum phase transition both in the symmetric ground state and in the…

Statistical Mechanics · Physics 2012-09-24 Bruno Tomasello , Davide Rossini , Alioscia Hamma , Luigi Amico

We present a non-demolition quantum information processing task of probing the information of a class of quantum state. In this task, the information is extracted by some unitary evolution with the introduced probing qubit assisted, but the…

Quantum Physics · Physics 2015-06-16 Chang-shui Yu , Jia-sen Jin , Heng Fan , He-shan Song

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