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Related papers: Non-Gaussian quantum discord for Gaussian states

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In standard coherent state teleportation with shared two-mode squeezed vacuum (TMSV) state there is a trade-off between the teleportation fidelity and the fidelity of estimation of the teleported state from results of the Bell measurement.…

Quantum Physics · Physics 2009-11-11 Ladislav Mišta

Quantum Gaussian states can be considered as the majority of the practical quantum states used in quantum communications and more generally in quantum information. Here we consider their properties in relation with the geometrically uniform…

Quantum Physics · Physics 2014-10-21 Gianfranco Cariolaro , Roberto Corvaja , Gianfranco Pierobon

The separability of bipartite non-Gaussian states is studied by applying the realignment criterion with the technique of functional analysis. The realignment criterion is given as one inequality in contrast to the infinitive number of…

Quantum Physics · Physics 2014-02-05 Xiao-yu Chen , Li-zhen Jiang , Ping Yu , Mingzhen Tian

Quantum discord has been studied extensively as a measure of non-classical correlations which includes entanglement as a subset. Although it is well known that non-zero discord can exist without entanglement, the origin of quantum discord…

Quantum Physics · Physics 2017-08-02 Yu Guo , Sumit Goswami

We address the issue of reducing the resource required to compute information-theoretic quantum correlation measures like quantum discord and quantum work deficit in two qubits and higher dimensional systems. We show that determination of…

Quantum Physics · Physics 2015-12-18 Titas Chanda , Tamoghna Das , Debasis Sadhukhan , Amit Kumar Pal , Aditi Sen De , Ujjwal Sen

We investigate evolution of quantum correlations in ensembles of two-qubit nuclear spin systems via nuclear magnetic resonance techniques. We use discord as a measure of quantum correlations and the Werner state as an explicit example. We…

Quantum Physics · Physics 2012-10-31 Hemant Katiyar , Soumya Singha Roy , T. S. Mahesh , Apoorva Patel

We study a general corresponding principle between discrete-variable quantum states and continuous-variable (especially, restricted on Gaussian) states via quantum purification method. In the previous work, we have already investigated an…

Quantum Physics · Physics 2019-01-03 Youngrong Lim , Jaewan Kim , Soojoon Lee , Kabgyun Jeong

Cubic phase states provide the essential non-Gaussian resource for continuous-variable quantum computing. We show that they also offer significant potential for quantum metrology, surpassing the phase-sensing sensitivity of all Gaussian…

Quantum Physics · Physics 2025-12-04 Jiajie Guo , Shuheng Liu , Boxuan Jing , Qiongyi He , Manuel Gessner

Quantum non-Gaussianity is a key resource for quantum advantage in continuous-variable systems. We introduce a general framework to quantify non-Gaussianity based on correlation generation: two copies of a state become correlated at a…

Quantum Physics · Physics 2025-08-28 Oliver Hahn , Ryuji Takagi

We introduce a measure of quantum correlations in the $N$-qubit quantum system which is invariant with respect to the $SU(2^N)$ group of transformations of this system. This measure is a modification of the quantum discord introduced…

Quantum Physics · Physics 2011-10-18 A. I. Zenchuk

In this paper, a computable multipartite multimode Gaussian quantum correlation measure ${\mathcal M}^{(k)}$ is proposed for any $k$-partite continuous-variable (CV) systems with $k\geq 2$. ${\mathcal M}^{(k)}$ depends only on the…

Quantum Physics · Physics 2022-03-01 Jinchuan Hou , Liang Liu , Xiaofei Qi

We study the dynamics of geometric measure of quantum discord (GMQD) under the influences of two local phase damping noises. Consider the two qubits initially in arbitrary X-states, we find the necessary and sufficient conditions for which…

Quantum Physics · Physics 2015-10-20 Wei Song , Zhuo-Liang Cao

We propose a global measure for quantum correlations in multipartite systems, which is obtained by suitably recasting the quantum discord in terms of relative entropy and local von Neumann measurements. The measure is symmetric with respect…

Quantum Physics · Physics 2011-11-28 C. C. Rulli , M. S. Sarandy

Quantum technologies exploit entanglement to enhance various tasks beyond their classical limits including computation, communication and measurements. Quantum metrology aims to increase the precision of a measured quantity that is…

Quantum Physics · Physics 2020-08-25 Bálint Koczor , Suguru Endo , Tyson Jones , Yuichiro Matsuzaki , Simon C. Benjamin

We explore experimentally the space of two-qubit quantum correlated mixed states, including frontier ones as defined by the use of quantum discord and von Neumann entropy. Our experimental setup is flexible enough to allow for the…

Quantum Physics · Physics 2011-08-31 Andrea Chiuri , Giuseppe Vallone , Mauro Paternostro , Paolo Mataloni

Quantum state discrimination plays a central role in quantum information and communication. For the discrimination of optical quantum states, the two most widely adopted measurement techniques are photon detection, which produces discrete…

Quantum Physics · Physics 2026-03-11 James Moran , Spiros Kechrimparis , Hyukjoon Kwon

One of the defining differences between classical and quantum systems is how measurements affect them. Here, we compare the approaches of contextuality and quantum discord in capturing quantum correlations in special classes of two-qubit…

Quantum Physics · Physics 2022-08-11 Asma Al-Qasimi

We provide experimental evidence of quantum features in bi-partite states classified as entirely classical according to a conventional criterion based on the Glauber P-function but possessing non-zero Gaussian quantum discord. Their quantum…

Non-Gaussian states are essential resources in quantum information processing. In this work, we investigate methods for quantifying bosonic non-Gaussianity in many-body systems. Building on recent theoretical insights into the…

Quantum Physics · Physics 2025-07-15 Kaifeng Bu , Bikun Li

The dynamics of a geometric measure of the quantum discord (GMQD) under decoherence is investigated. We show that the GMQD of a two-qubit state can be alternatively obtained through the singular values of a $3\times4$ matrix whose elements…

Quantum Physics · Physics 2010-09-07 Xiao-Ming Lu , Zheng-Jun Xi , Zhe Sun , Xiaoguang Wang