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Related papers: Revisiting Quantum discord for two-qubit X states:…

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We present a numerical framework for the certification and systematic analysis of the relationship between Bell nonlocality and quantum discord. By determining the minimum discord required for a bipartite state to manifest a specific Bell…

Quantum Physics · Physics 2026-05-06 Robert Okuła , Adrian Misiak , Piotr Mironowicz

Understanding algorithmic error accumulation in quantum simulation is crucial due to its fundamental significance and practical applications in simulating quantum many-body system dynamics. Conventional theories typically apply the triangle…

Quantum Physics · Physics 2024-11-11 Boyang Chen , Jue Xu , Qi Zhao , Xiao Yuan

For the XXZ subclass of symmetric two-qubit X states, we study the behavior of quantum conditional entropy S_{cond} as a function of measurement angle \theta\in[0,\pi/2]. Numerical calculations show that the function S_{cond}(\theta) for X…

Quantum Physics · Physics 2017-09-14 M. A. Yurischev

It is often assumed that the ancilla qubits required for encoding a qubit in quantum error correction (QEC) have to be in pure states, $|00...0>$ for example. In this letter, we seek an encoding scheme, in which the ancillae may be in a…

Quantum Physics · Physics 2013-08-21 Yasushi Kondo , Chiara Bagnasco , Mikio Nakahara

Quantum discord, as a measure of all quantum correlations, has been proposed as the key resource in certain quantum communication tasks and quantum computational models without containing much entanglement. Daki\'{c}, Vedral, and Brukner…

Quantum Physics · Physics 2013-02-05 Hai-Rui Wei , Bao-Cang Ren , Fu-Guo Deng

The study of quantum correlations in High-dimensional bipartite systems is crucial for the development of quantum computing. We propose relative entropy as a distance measure of correlations may be measured by means of the distance from the…

Quantum Physics · Physics 2016-04-12 M. Mahdian , M. B. Arjmandi

In the present article, based on the formalism introduced in [Loubenets, J. Math. Phys. 53, 022201 (2012)], we derive for a pure bipartite quantum state a new upper bound on its maximal violation of general Bell inequalities. This new bound…

Quantum Physics · Physics 2021-10-19 Elena R. Loubenets , Min Namkung

Quantum discord is a form of correlation that is defined as the difference between quantum and classical mutual information of two parties. Due to the optimization involved in the definition of classical mutual information of quantum…

Quantum Physics · Physics 2024-01-23 Narjes Taghadomi , Azam Mani , Ali Fahim , Ali Bakoui , Mohammad Sadegh Salami

The counterintuitive effect of non-unique ordering of two-qubit states with quantum entanglement measures was discovered over ten years ago. More precisely, it was shown by Monte Carlo simulations that there exist states for which the…

Quantum Physics · Physics 2012-07-17 Małgorzata Okrasa , Zbigniew Walczak

We consider a state discrimination problem which deals with settings of minimum-error and unambiguous discrimination systematically by introducing a margin for the probability of an incorrect guess. We analyze discrimination of three…

Quantum Physics · Physics 2012-10-12 H. Sugimoto , Y. Taninaka , A. Hayashi

Radhakrishnan \emph{et.al} [Phys. Rev. Lett. \textbf{124}, 110401 (2020)] proposed quantum discord to multipartite systems and derived explicit formulae for any states. These results are significant in capturing quantum correlations for…

Quantum Physics · Physics 2021-07-01 Chen-Lu Zhu , Bin Hu , Bo Li , Zhi-Xi Wang , Shao-Ming Fei

Analysis of quantum error correcting codes is typically done using a stochastic, Pauli channel error model for describing the noise on physical qubits. However, it was recently found that coherent errors (systematic rotations) on physical…

Quantum Physics · Physics 2018-01-09 Daniel Greenbaum , Zachary Dutton

The geometric discord $\mathcal{D}$ of a state is a measure of the quantumness of the state and the negativity $\mathcal{N}$ is a measure of the entanglement of a state. It was proved by D. Girolami and G. Adesso that for states on…

Quantum Physics · Physics 2019-10-08 Priyabrata Bag , Santanu Dey , Hiroyuki Osaka

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

It is known from the analysis of the density matrix for bipartite systems that the quantum discord (as a measure of quantum correlations) depends on the particular subsystem chosen for the projective measurements. We study asymmetry of the…

Quantum Physics · Physics 2015-05-27 E. B. Fel'dman , A. I. Zenchuk

Quantum fidelity is a central tool in quantum information, quantifying how much two quantum states are similar. Here we propose a limit formula for the quantum fidelity between a mixed state and a pure state. As an example of an…

Quantum Physics · Physics 2014-10-13 Gaetana Spedalieri , Christian Weedbrook , Stefano Pirandola

We improve the recent method of Wang et. al to calculate exactly the one-way information deficit of any X-state. Analytical formulas of the one-way information deficit are given for several nontrivial regions of the parameters.

Quantum Physics · Physics 2015-11-23 Naihuan Jing , Xia Zhang , Yao-Kun Wang

The problem of discriminating with minimum error between two mixed quantum states is reviewed, with emphasize on the detection operators necessary for performing the measurement. An analytical result is derived for the minimum probability…

Quantum Physics · Physics 2009-11-10 Ulrike Herzog

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 problem of unambiguous state discrimination consists of determining which of a set of known quantum states a particular system is in. One is allowed to fail, but not to make a mistake. The optimal procedure is the one with the lowest…

Quantum Physics · Physics 2009-11-07 Mark Hillery , Jihane Mimih