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We discuss the possibility of observing quantum nonlocality using the so-called mode entanglement, analyzing the differences between different types of particles in this context. We first discuss the role of coherent states in such…

Quantum Physics · Physics 2007-11-22 S. Ashhab , Koji Maruyama , Franco Nori

We study the separability of permutationally symmetric quantum states. We show that for bipartite symmetric systems most of the relevant entanglement criteria coincide. However, we provide a method to generate examples of bound entangled…

Quantum Physics · Physics 2009-05-12 Geza Toth , Otfried Gühne

Quantum mechanics of composite systems, gives rise to certain special states called entangled states. A physical system, that is in an entangled state displays an intricate correlation between its subsystems. There are also some composite…

Quantum Physics · Physics 2009-07-13 S. Kanmani

One of the key manifestations of quantum mechanics is the phenomenon of quantum entanglement. While the entanglement of bipartite systems is already well understood, our knowledge of entanglement in multipartite systems is still limited.…

Quantum Physics · Physics 2022-04-29 Adam Burchardt

We introduce a generalization of entanglement based on the idea that entanglement is relative to a distinguished subspace of observables rather than a distinguished subsystem decomposition. A pure quantum state is entangled relative to such…

Quantum Physics · Physics 2009-11-10 Howard Barnum , Emanuel Knill , Gerardo Ortiz , Rolando Somma , Lorenza Viola

We relate the notion of entanglement for quantum systems composed of two identical constituents to the impossibility of attributing a complete set of properties to both particles. This implies definite constraints on the mathematical form…

Quantum Physics · Physics 2007-05-23 GianCarlo Ghirardi , Luca Marinatto

Entanglement in fermion many-body systems is studied using a generalized definition of separability based on partitions of the set of observables, rather than on particle tensor products. In this way, the characterizing properties of…

Quantum Physics · Physics 2014-03-20 F. Benatti , R. Floreanini , U. Marzolino

Coherent states with large amplitudes are traditionally thought of as the best quantum mechanical approximation of classical behavior. Here we argue that, far from being classical, coherent state are in fact highly entangled. We demonstrate…

Quantum Physics · Physics 2007-05-23 D. Kaszlikowski , V. Vedral

The study of entanglement in systems composed of identical particles raises interesting challenges with far-reaching implications in both, our fundamental understanding of the physics of composite quantum systems, and our capability of…

Quantum Physics · Physics 2023-03-31 A. P. Majtey , A. Valdés-Hernández , E. Cuestas

We consider quantum systems in entangled states post-selected in non-entangled states. Such systems exhibit unusual behavior, in particular when weak measurements are performed at intermediate times.

Quantum Physics · Physics 2015-06-12 Yakir Aharonov , Shmuel Nussinov , Sandu Popescu , Lev Vaidman

We characterize entanglement subject to its definition over real and complex, composite quantum systems. In particular, a method is established to assess quantum correlations with respect to a selected number system, illuminating the deeply…

We explore the subtle relationships between partial separability and entanglement of subsystems in multiqubit quantum states and give experimentally accessible conditions that distinguish between various classes and levels of partial…

Quantum Physics · Physics 2008-09-03 Michael Seevinck , Jos Uffink

An entangled state is bound entangled, if one cannot combine any number of copies of the state to a maximally entangled state, by using only local operations and classical communication. If one formalizes this notion of bound entanglement,…

Quantum Physics · Physics 2026-02-05 Michael Gaida , Matthias Kleinmann

The concept of entangled quantum states is considered in the context of systems of identical particles, based on the requirement that in order to represent physical states both for the overall system and the sub-systems which may be…

Quantum Physics · Physics 2014-01-03 Bryan Dalton , Libby Heaney , John Goold , Thomas Busch , Barry Garraway

The density matrix of composite spin system is discussed in relation to the adjoint representation of unitary group U(n). The entanglement structure is introduced as an additional ingredient to the description of the linear space carrying…

Quantum Physics · Physics 2007-05-23 V. I. Man'ko , G. Marmo , E. C. G. Sudarshan , F. Zaccaria

The entangled quantum states play a key role in quantum information. The association of the quantum state vector with each individual physical system in an attributive way is a source of many false paradoxes and inconsistencies. The…

Quantum Physics · Physics 2007-10-15 M. Kupczynski

We discuss the question of entanglement versus separability of pure quantum states in direct product Hilbert spaces and the relevance of this issue to physics. Different types of separability may be possible, depending on the particular…

Quantum Physics · Physics 2009-11-07 Jon Eakins , George Jaroszkiewicz

Non-classical states that are characterized by their non-positive quasi-probabilities in phase space are known to be the basis for various quantum effects. In this work, we investigate the interrelation between the non-classicality and…

Quantum Physics · Physics 2010-10-12 Kisik Kim , Jaewan Kim , Joonwoo Bae

We review two general criteria for deciding whether a pure bipartite quantum state describing a system of two identical particles is entangled or not. The first one considers the possibility of attributing a complete set of objective…

Quantum Physics · Physics 2009-11-11 GianCarlo Ghirardi , Luca Marinatto

Quantum information is about the entanglement of states. To this starting point we add parameters whereby a single state becomes a non-vanishing section of a bundle. We consider through examples the possible entanglement patterns of…

Quantum Physics · Physics 2023-11-23 M. H. Freedman , M. B. Hastings