English
Related papers

Related papers: Necessary and sufficient condition for non-zero qu…

200 papers

We argue that the geometric discord introduced in [B. Dakic, V. Vedral, and C. Brukner, Phys. Rev. Lett. 105, 190502 (2010)] is not a good measure for the quantumness of correlations, as it can increase even under trivial local reversible…

Quantum Physics · Physics 2014-10-16 Marco Piani

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

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

Recently, the fast development of quantum technologies led to the need for tools allowing the characterization of quantum resources. In particular, the ability to estimate non-classical aspects, e.g. entanglement and quantum discord, in…

We extend the geometric measure of quantum discord, introduced and computed for two-qubit states in [B. Dakic, C. Brukner, and V. Vedral, Phys. Rev. Lett. 105, 190502 (2010)], to quantify non-classical correlations in composite Gaussian…

Quantum Physics · Physics 2011-12-13 Gerardo Adesso , Davide Girolami

In this paper, we present the concept of the one-way unlocalizable quantum discord and investigate its properties. We provide a polygamy inequality for it in tripartite pure quantum system of arbitrary dimension. Several tradeoff relations…

Quantum Physics · Physics 2013-05-30 Zhengjun Xi , Heng Fan , Yongming Li

We discuss how to calculate genuine multipartite quantum and classical correlations in symmetric, spatially invariant, mixed $n$-qubit density matrices. We show that the existence of symmetries greatly reduces the amount of free parameters…

Quantum Physics · Physics 2016-10-24 Gian Luca Giorgi , Steve Campbell

We discuss the realization of quantum advantage in a system without quantum entanglement but with non-zero quantum discord. We propose an optical realization of symmetric two-qubit $X$-states with controllable anti-diagonal elements. This…

Quantum Physics · Physics 2017-06-07 A. Maldonado-Trapp , Pablo Solano , Anzi Hu , Charles W. Clark

Quantum discord and quantum uncertainty are two important features of the quantum world. In this work, the relation between entropic uncertainty relation and the shareability of quantum discord is studied. First, by using tripartite…

Quantum Physics · Physics 2021-08-02 Hazhir Dolatkhah , Abolhassan Mohammadi , Soroush Haseli

We investigate the dynamics of quantum discord and entanglement for a class of mixed qubit-qutrit states assuming that only the qutrit is under the action of a dephasing channel. We demonstrate that even though the entanglement in the…

Quantum Physics · Physics 2013-04-02 G. Karpat , Z. Gedik

It is shown that the dissonance, a quantum correlation which is equal to quantum discord for separable state, is required for assisted optimal state discrimination. We find that only one side discord is required in the optimal process of…

Quantum Physics · Physics 2012-02-24 Bo Li , Shao-Ming Fei , Zhi-Xi Wang , Heng Fan

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 exact solutions of the super quantum discord are derived for general two qubit X states in terms of a one-variable function. Several exact solutions of the super quantum discord are given for the general X-state over nontrivial regions…

Quantum Physics · Physics 2017-03-06 Naihuan Jing , Bing Yu

It is known that quantum discord might experience a sudden transition in its dynamics when calculated for certain Bell-diagonal states (BDS) that are in interaction with their surroundings. We examine this phenomenon known as the sudden…

Quantum Physics · Physics 2013-10-01 João P. G. Pinto , Goktug Karpat , Felipe F. Fanchini

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

This paper summarizes the basics of the notion of quantum discord and how it relates to other types of correlations in quantum physics. We take the fundamental information theoretic approach and illustrate our exposition with a number of…

Quantum Physics · Physics 2017-02-07 Vlatko Vedral

Classical correlation and quantum discord are computed for two-qubit $X$-states. Our approach, which is inspired by the methods of classical polarization optics, is geometric in the sense that the entire analysis is tied to the correlation…

Quantum Physics · Physics 2013-11-04 Krishna Kumar Sabapathy , R. Simon

It is known that a reliable geometric quantifier of discord-like correlations can be built by employing the so-called trace distance. This is used to measure how far the state under investigation is from the closest "classical-quantum" one.…

Quantum Physics · Physics 2014-01-24 F. Ciccarello , T. Tufarelli , V. Giovannetti

We introduce the quantum-house effect, a non-local phenomenon which apparently does not require quantum discord to be present. It suffices for the effect if neither subsystem of a bipartite system is in a pure state. This way, the…

Quantum Physics · Physics 2022-12-20 Tamás Varga

Criteria of measure quantifying quantum coherence, a unique property of quantum system, are proposed recently. In this paper, we first give an uncertainty-like expression relating the coherence and the entropy of quantum system. This…

Quantum Physics · Physics 2015-07-15 Zhengjun Xi , Yongming Li , Heng Fan