English
Related papers

Related papers: Characterizing quantum correlations in the nonsign…

200 papers

We provide a novel criterion for identifying quantum correlation, which allows us to find connections between Bell type inequalities, entanglement detection, and correlation. We utilize the criterion to construct witness operators that can…

Quantum Physics · Physics 2007-05-23 Che-Ming Li , Li-Yi Hsu , Wei-Yang Lin , Yueh-Nan Chen , Der-San Chuu , Tobias Brandes

Based on the relative entropy, we give a unified characterization of quantum correlations for nonlocality, steerability, discord and entanglement for any bipartite quantum states. For two-qubit states we show that the quantities obtained…

Quantum Physics · Physics 2017-04-14 Tinggui Zhang , Hong Yang , Xianqing Li-Jost , Shao-Ming Fei

Non-local correlations are among the most fascinating features of quantum theory from the point of view of information: Such correlations, although not allowing for signaling, are unexplainable by pre-shared information. The correlations…

Quantum Physics · Physics 2014-01-21 Helen Ebbe , Stefan Wolf

We present six new measures of nonlocal correlation for discrete multipartite quantum systems; correlance, statance, probablance, strong discordance, discordance, and diagonal discordance. The correlance measures all nonlocal correlation…

Quantum Physics · Physics 2020-06-02 Samuel R. Hedemann

We show that two qubits, initially in a fully classical state, can develop significant quantum correlations as measured by the quantum discord (QD) under the action of a local memoryless noise (specifically we consider the case of a…

Quantum Physics · Physics 2012-02-10 Francesco Ciccarello , Vittorio Giovannetti

The future progress of semi-device independent quantum information science depends crucially on our ability to bound the strength of the nonlocal correlations achievable with finite dimensional quantum resources. In this work, we…

Quantum Physics · Physics 2014-02-05 Miguel Navascues , Gonzalo de la Torre , Tamas Vertesi

While entanglement is a cornerstone of quantum theory and holography, quantum correlations arising from superposition, such as quantum discord, offer a broader perspective that has remained largely unexplored in holography. We construct…

High Energy Physics - Theory · Physics 2026-02-11 Takato Mori

The exploration of entanglement and Bell non-locality among multi-particle quantum systems offers a profound avenue for testing and understanding the limits of quantum mechanics and local real hidden variable theories. In this work, we…

Quantum Physics · Physics 2025-10-23 Paweł Horodecki , Kazuki Sakurai , Abhyoudai S. Shaleena , Michael Spannowsky

I introduce a framework in which a variety of probabilistic theories can be defined, including classical and quantum theories, and many others. From two simple assumptions, a tensor product rule for combining separate systems can be…

Quantum Physics · Physics 2007-05-23 Jonathan Barrett

One of the most important questions in quantum information theory is the so-called separability problem. It involves characterizing the set of separable (or, equivalently entangled) states among mixed states of a multipartite quantum…

Quantum Physics · Physics 2014-12-16 Michał Oszmaniec

We propose a measure of non-classical correlations in bipartite quantum states based on local unitary operations. We prove the measure is non-zero if and only if the quantum discord is non-zero; this is achieved via a new characterization…

Quantum Physics · Physics 2013-06-25 Sevag Gharibian

A non-local box is a virtual device that has the following property: given that Alice inputs a bit at her end of the device and that Bob does likewise, it produces two bits, one at Alice's end and one at Bob's end, such that the XOR of the…

Quantum Physics · Physics 2012-02-22 A. Broadbent , A. A. Methot

A generalization of quantum discord to multipartite systems is proposed. A key feature of our formulation is its consistency with the conventional definition of discord in bipartite systems. It is by construction zero only for systems with…

Quantum Physics · Physics 2020-03-25 Chandrashekar Radhakrishnan , Mathieu Lauriere , Tim Byrnes

It is a well-established fact that some quantum correlations can be nonlocal, meaning that they cannot be described by a local hidden variable model. Certain quantum correlations have a form of nonlocality so strong that they cannot be…

Quantum Physics · Physics 2026-04-30 Martin J. Renner , Edwin Peter Lobo , Arturo Konderak , Remigiusz Augusiak , Antonio Acín

A classical non-signalling (or causal) box is an operation on classical bipartite input with classical bipartite output such that no signal can be sent from a party to the other through the use of the box. The quantum counterpart of such…

Quantum Physics · Physics 2009-11-11 M. Piani , M. Horodecki , P. Horodecki , R. Horodecki

We analyze nonclassical correlations between outcomes of measurements conducted on two spatial radiation modes. These correlations cannot be simulated with statistical mixtures of coherent states or, more generally, with non-negative…

Quantum Physics · Physics 2022-07-01 V. S. Kovtoniuk , I. S. Yeremenko , S. Ryl , W. Vogel , A. A. Semenov

Quantum correlations represent a fundamental tool for studies ranging from basic science to quantum technologies. Different non-classical correlations have been identified and studied, as entanglement and discord. In view of future…

Quantum Physics · Physics 2016-12-15 E. Moreva , M. Gramegna , M. A. Yurischev , M. Genovese

The non-Markovian decoherence of quantum and classical correlations is analytically obtained when two qubits are asymmetrically subjected to the bit flip channel and phase flip channel. For one class of initial mixed states, quantum…

Quantum Physics · Physics 2012-08-09 Xiang Hao , Tao Pan , Jinqiao Sha

For the bipartite Bell scenario with two inputs and two outputs, a nonlinear witness of dimensionally restricted nonlocality is introduced. Popescu-Rohrlich (PR) box fraction of dimensionally restricted nonlocality is then introduced and…

Quantum Physics · Physics 2026-03-06 Chellasamy Jebarathinam

In this didactic article we explore the concept of quantum correlations beyond entanglement. We begin by introducing and motivating the classically correlated states and then showing how to quantify the quantum correlations using an…

Quantum Physics · Physics 2016-11-08 Gerardo Adesso , Marco Cianciaruso , Thomas R. Bromley