English
Related papers

Related papers: Quantum Discord for Generalized Bloch Sphere State…

200 papers

Entangled quantum states are regarded as a key resource in quantum key distribution (QKD) protocols. However, quantum correlations, other than entanglement can also play a significant role in the QKD protocols. In this work, we will focus…

Quantum Physics · Physics 2025-12-09 Rashi Jain , Satyabrata Adhikari

We discuss some properties of the quantum discord based on the geometric distance advanced by Dakic, Vedral, and Brukner [Phys. Rev. Lett. {\bf 105}, 190502 (2010)], with emphasis on Werner- and MEM-states. We ascertain just how good the…

Quantum Physics · Physics 2011-03-25 J. Batle , A. Plastino , A. R. Plastino , M. Casas

In a pair of correlated quantum systems a measurement in one corresponds to a change in the state of the other. In the process, information is lost. Measurement along which set of projectors would accompany minimum loss in information…

Quantum Physics · Physics 2022-05-19 Chitradeep Gupta

There has been an increasing interest in exploring quantities associated with quantum information at colliders. We perform a detailed analysis describing how to measure the quantum discord in the top anti-top quantum state at the Large…

High Energy Physics - Phenomenology · Physics 2025-03-05 Tao Han , Matthew Low , Navin McGinnis , Shufang Su

Among various definitions of quantum correlations, quantum discord has attracted considerable attention. To find analytical expression of quantum discord is an intractable task. In this paper, we discuss thoroughly the case of two-qubit…

Quantum Physics · Physics 2015-05-28 Mingjun Shi , Wei Yang , Fengjian Jiang , Jiangfeng Du

Using the convex optimization method and Helstrom family of ensembles introduced in Ref. [1], we have discussed optimal ambiguous discrimination in qubit systems. We have analyzed the problem of the optimal discrimination of N known quantum…

Quantum Physics · Physics 2016-09-26 M. A. Jafarizadeh , Y. Mazhari , M. Aali

We derive a general approximate solution to the problem of minimizing the conditional entropy of a qudit-qubit system resulting from a local projective measurement on the qubit, which is valid for general entropic forms and becomes exact in…

Quantum Physics · Physics 2015-06-22 N. Gigena , R. Rossignoli

We investigate multipartite entanglement for composite quantum systems in a pure state. Using the generalized Bloch representation for n-qubit states, we express the condition that all k-qubit reductions of the whole system are maximally…

Quantum Physics · Physics 2013-02-01 Ludovic Arnaud , Nicolas J. Cerf

We highlight an information-theoretic meaning of quantum discord as the gap between the ac- cessible information and the Holevo bound in the framework of ensemble of quantum states. This complementary relationship implies that a large…

Quantum Physics · Physics 2013-03-21 Yao Yao , Jing-Zheng Huang , Xu-Bo Zou , Zhen-Qiang Yin , Wei Chen , Guang-Can Guo , Zheng-Fu Han

A symmetric measure of quantum correlation based on the Hilbert-Schmidt distance is presented in this paper. For two-qubit states, we simplify considerably the optimization procedure so that numerical evaluation can be performed…

Quantum Physics · Physics 2011-07-18 Mingjun Shi , Fengjian Jiang , Jiangfeng Du

Understanding the structure of multi-qubit quantum states is essential for both quantum information research and education, yet intuitive visualization beyond the single-qubit Bloch sphere remains challenging. In this work, we propose a…

Quantum Physics · Physics 2026-03-11 Satoru Shoji

Quantum discord represents a correlation beyond classicality that could be useful for many quantum information tasks, and therefore is viewed as a valuable quantum resource. Theoretically, whether a bipartite quantum state has a non-zero…

Quantum Physics · Physics 2025-06-10 Rong Wang , Yao Yao , Zhen-Qiang Yin

We propose a new criterion to judge zero quantum discord for arbitrary bipartite states. A bipartite quantum state has zero quantum discord if and only if all blocks of its density matrix are normal matrices and commute with each other.…

Quantum Physics · Physics 2015-03-19 Jie-Hui Huang , Lei Wang , Shi-Yao Zhu

We give the explicit expressions of the pairwise quantum correlations present in superpositions of multipartite coherent states. A special attention is devoted to the evaluation of the geometric quantum discord. The dynamics of quantum…

Quantum Physics · Physics 2015-06-11 M. Daoud , R. Ahl Laamara

Multipartite Quantum Correlations is one of the most relevant indicator of the quantumness of a system in many body systems. This remarkable feature is in general difficult to characterize and the known definitions are hard to measure.…

Quantum Physics · Physics 2014-11-26 Raul Coto , Miguel Orszag

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

We extend the quantum discord to continuous variable systems and evaluate Gaussian quantum discord C(\rho) for bipartite Gaussian states. In particular, for squeezed thermal states (STS), we explicitly maximize the extractable information…

Quantum Physics · Physics 2015-05-18 Paolo Giorda , Matteo G. A. Paris

Quantum discord, a key indicator of non-classical correlations in bipartite systems, has been recently extended to multipartite scenarios [Phys. Rev. Lett. 2020, 124:110401]. We present exact analytic formulas for the quantum discord of…

Quantum Physics · Physics 2025-03-21 Jianming Zhou , Xiaoli Hu , Honglian Zhang , Naihuan Jing

We advocate the step change in properties of discrete $d$-level quantum systems, between $d=2$ and $d\geq 3$. Qubit systems, or multipartite systems containing qubit subsystem, are exceptional in their relative simplicity. One faces a step…

Quantum Physics · Physics 2017-04-26 Andrzej Frydryszak , Lech Jakóbczyk , Piotr Ługiewicz

We introduce the notion of quantum dissension for a three-qubit system as a measure of quantum correlations. We use three equivalent expressions of three-variable mutual information. Their differences can be zero classically but not so in…

Quantum Physics · Physics 2012-04-05 Indranil Chakrabarty , Pankaj Agrawal , Arun K. Pati