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We devise a protocol in which general non-classical multipartite correlations produce a physically relevant effect, leading to the creation of bipartite entanglement. In particular, we show that the relative entropy of quantumness, which…

In a recent work [S. Asthana. New Journal of Physics 24.5 (2022): 053026], we have shown the interrelation of different nonclassical correlations in multiqubit systems with quantum coherence in a single logical qubit. In this work, we…

Quantum Physics · Physics 2023-03-21 Sooryansh Asthana , V. Ravishankar

Mode-entanglement based criteria and measures become insufficient for broadband emission, e.g. from spasers (plasmonic nano-lasers). We introduce criteria and measures for the (i) total entanglement of two wavepackets, (ii) entanglement of…

Quantum Physics · Physics 2020-07-01 Mehmet Emre Tasgin , Mehmet Gunay , M. Suhail Zubairy

We derive a classification and a measure of classical- and quantum-correlation of multipartite qubit, qutrit, and in general, $n$-level systems, in terms of SU$(n)$ representations of density matrices. We compare the measure for the case of…

Quantum Physics · Physics 2010-10-26 Y. B. Band , I. Osherov

Practically applicable criteria for the nonclassicality of quantum states are formulated in terms of different types of moments. For this purpose the moments of the creation and annihilation operators, of two quadratures, and of a…

Quantum Physics · Physics 2009-11-11 E. V. Shchukin , W. Vogel

One of the most striking features of quantum theory is the existence of entangled states, responsible for Einstein's so called "spooky action at a distance". These states emerge from the mathematical formalism of quantum theory, but to date…

Quantum Physics · Physics 2017-08-30 Jonathan G. Richens , John H. Selby , Sabri W. Al-Safi

Is entanglement an exclusive feature of quantum systems, or is it common to all non-classical theories? And if this is the case, how strong is quantum mechanical entanglement as compared to that exhibited by other theories? The first part…

Quantum Physics · Physics 2018-03-09 Ludovico Lami

A precise physical description and understanding of the classical dual content of quantum theory is necessary in many disciplines today: from concepts and interpretation to quantum technologies and computation. In this paper we investigate…

Quantum Physics · Physics 2025-12-01 Diego J. Cirilo-Lombardo , Norma G. Sanchez

A number of noncontextual models exist which reproduce different subsets of quantum theory and admit a no-cloning theorem. Therefore, if one chooses noncontextuality as one's notion of classicality, no-cloning cannot be regarded as a…

Quantum Physics · Physics 2020-04-29 Matteo Lostaglio , Gabriel Senno

We establish the nonclassicality of continuous-variable states as a resource for quantum metrology. Based on the quantum Fisher information of multimode quadratures, we introduce the metrological power as a measure of nonclassicality with a…

Quantum Physics · Physics 2019-02-06 Hyukjoon Kwon , Kok Chuan Tan , Tyler Volkoff , Hyunseok Jeong

Entanglement is often regarded as an inherently quantum feature. We show that this does not have to be the case: under restricted operational access, classical correlations can appear nonseparable when expressed in the formalism of quantum…

Quantum Physics · Physics 2025-12-18 Samuel Schlegel , Borivoje Dakić , Flavio Del Santo

We propose a general argument to show that if a physical system can mediate locally the generation of entanglement between two quantum systems, then it itself must be non-classical. Remarkably, we do not assume any classical or quantum…

Quantum Physics · Physics 2020-10-21 Chiara Marletto , Vlatko Vedral

Nonclassical states of a quantized light are described in terms of Glauber-Sudarshan P distribution which is not a genuine classical probability distribution. Despite several attempts, defining a uniform measure of nonclassicality (NC) for…

Quantum Physics · Physics 2020-10-20 Soumyakanti Bose

Inspired by its fundamental importance in quantum mechanics, we define and study the notion of entanglement for abstract physical theories, investigating its profound connection with the concept of superposition. We adopt the formalism of…

Quantum Physics · Physics 2019-10-11 Guillaume Aubrun , Ludovico Lami , Carlos Palazuelos

We report the direct -- continuous in phase -- sampling of a regularized $P$ function, the so-called nonclassicality quasiprobability, for squeezed light. Through their negativities, the resulting phase-space representation uncovers the…

Quantum Physics · Physics 2015-09-23 E. Agudelo , J. Sperling , W. Vogel , S. Köhnke , M. Mraz , B. Hage

We study the local indistinguishability problem of quantum states. By introducing an easily calculated quantity, non-commutativity, we present an criterion which is both necessary and sufficient for the local indistinguishability of a…

Quantum Physics · Physics 2014-09-17 Teng Ma , Ming-Jing Zhao , Yao-Kun Wang , Shao-Ming Fei

Article presents general formulation of entanglement measures problem in terms of correlation function. Description of entanglement in probabilistic framework allow us to introduce new quantity which describes quantum and classical…

Quantum Physics · Physics 2007-05-23 S. Bugajski , J. A. Miszczak

There are several examples of bipartite entangled states of continuous variables for which the existing criteria for entanglement using the inequalities involving the second order moments are insufficient. We derive new inequalities…

Quantum Physics · Physics 2016-08-08 G. S. Agarwal , Asoka Biswas

The degree of nonclassicality of states of a field mode is analysed considering both phase-space and distance-type measures of nonclassicality. By working out some general examples, it is shown explicitly that the phase-space measure is…

Quantum Physics · Physics 2009-11-07 J. M. C. Malbouisson , B. Baseia

Entanglement appears under two different forms in quantum theory, namely as a property of states of joint systems and as a property of measurement eigenstates in joint measurements. By combining these two aspects of entanglement, it is…