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Related papers: Non-Gaussian quantum discord for Gaussian states

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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

We study nonclassical correlations beyond entanglement in a family of two-mode non-Gaussian states which represent the continuous-variable counterpart of two-qubit Werner states. We evaluate quantum discord and other quantumness measures…

Quantum Physics · Physics 2015-06-03 Richard Tatham , Ladislav Mišta , Gerardo Adesso , Natalia Korolkova

We study quantum correlations beyond entanglement in two-mode Gaussian states of continuous variable systems, by means of the measurement-induced disturbance (MID) and its ameliorated version (AMID). In analogy with the recent studies of…

Quantum Physics · Physics 2015-03-17 Ladislav Mišta, , Richard Tatham , Davide Girolami , Natalia Korolkova , Gerardo Adesso

Quantum discord is a measure of non-classical correlations, which are excess correlations inherent in quantum states that cannot be accessed by classical measurements. For multipartite states, the classically accessible correlations can be…

Quantum Physics · Physics 2019-09-18 Mark Bradshaw , Ping Koy Lam , Syed M. Assad

Quantum discord, a measure of genuinely quantum correlations, is generalized to continuous variable systems. For all two-mode Gaussian states, we calculate analytically the quantum discord and a related measure of classical correlations,…

Quantum Physics · Physics 2015-03-13 Gerardo Adesso , Animesh Datta

Consider two bosonic modes which are prepared in one of two possible Gaussian states with the same local energy: either a tensor-product thermal state (with zero correlations) or a separable Gaussian state with maximal correlations (with…

Quantum Physics · Physics 2019-08-06 Gaetana Spedalieri , Stefano Pirandola , Samuel L. Braunstein

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

Gaussian quantum discord is a measure of quantum correlations in Gaussian systems. Using Gaussian discord we quantify the quantum correlations of a bipartite entangled state and a separable two-mode mixture of coherent states. We…

Quantum Physics · Physics 2012-08-13 Lars S. Madsen , Adriano Berni , Mikael Lassen , Ulrik L. Andersen

Especially investigated in recent years, the Gaussian discord can be quantified by a distance between a given two-mode Gaussian state and the set of all the zero-discord two-mode Gaussian states. However, as this set consists only of…

Quantum Physics · Physics 2015-06-22 Paulina Marian , Tudor A. Marian

In this Letter we exploit the recently-solved conjecture on the bosonic minimum output entropy to show the optimality of Gaussian discord, so that the computation of quantum discord for bipartite Gaussian states can be restricted to local…

In this work we analyze a non-commutativity measure of quantum correlations recently proposed by Y. Guo [Sci. Rep. 6, 25241 (2016)]. By recourse to a systematic survey of a two-qubit system, we detected an undesirable behavior of such a…

Quantum Physics · Physics 2017-08-25 A. P. Majtey , D. Bussandri , T. M. Osán , P. W. Lamberti , A. Valdés-Hernández

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…

It has been proven that the quantum discord is a more general tool to capture non-classical correlation than quantum entanglement, because there is a non-zero quantum discord in several mixed states that could not be measured by quantum…

Quantum Physics · Physics 2015-03-20 N. Doustimotlagh

In the framework of the theory of open systems, we give a description of quantum entanglement and quantum discord for two non-interacting modes embedded in a thermal environment. We describe the evolution of entanglement in terms of the…

Quantum Physics · Physics 2015-06-12 Aurelian Isar

We define a new measure of quantum correlations in bipartite quantum systems given by the Bures distance of the system state to the set of classical states with respect to one subsystem, that is, to the states with zero quantum discord. Our…

Quantum Physics · Physics 2013-12-23 Dominique Spehner , Miguel Orszag

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

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

Quantum discord provides a measure for quantifying quantum correlations beyond entanglement and is very hard to compute even for two-qubit states because of the minimization over all possible measurements. Recently a simple algorithm to…

Quantum Physics · Physics 2011-10-10 Qing Chen , Chengjie Zhang , Sixia Yu , X. X. Yi , C. H. Oh

We address the experimental estimation of Gaussian quantum discord for two-mode squeezed thermal state, and demonstrate a measurement scheme based on a pair of homodyne detectors assisted by Bayesian analysis which provides nearly optimal…

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

Quantum Physics · Physics 2015-06-12 Aurelian Isar
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