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Related papers: On the Activation of Quantum Nonlocality

200 papers

Nonlocality is a key feature of quantum networks and is being studied for its potential applications in quantum communication and computing. Understanding and harnessing nonlocality in quantum networks could lead to the development of…

Quantum Physics · Physics 2025-06-27 Jun-Li Jiang , Xin-Zhu Liu , Xue Yang , Xiuyong Ding , Da Zhang , Ming-Xing Luo

We experimentally verify the link existing between entanglement and the amount of wave-particle duality in a bipartite quantum system, with superconducting qubits in the IBM Q quantum computer. We consider both pure and mixed states, and…

Quantum Physics · Physics 2021-02-17 Nicolas Schwaller , Marc-André Dupertuis , Clément Javerzac-Galy

As a striking manifestation of quantum entanglement, nonlocality has long played a pivotal role in shaping our understanding of the quantum world. When considering a Bell test involving three parties, we may even find a remarkable situation…

Quantum Physics · Physics 2026-04-10 Kai-Siang Chen , Gelo Noel M. Tabia , Chung-Yun Hsieh , Yu-Chun Yin , Yeong-Cherng Liang

Measurement correlations in quantum systems can exhibit non-local behavior, a fundamental aspect of quantum mechanics with applications such as device-independent quantum information processing. However, the explicit construction of local…

Quantum Physics · Physics 2025-04-30 Nick von Selzam , Florian Marquardt

Nonlocality is the most characteristic feature of quantum mechanics. John Bell, in his seminal 1964 work, proved that local-realism imposes a bound on the correlations among the measurement statistics of distant observers. Surpassing this…

This article describes a proposed way to conduct an experiment using a correlated particle pair in an entangled state, which leaves no room for any local models.

Quantum Physics · Physics 2015-09-28 Alexander V. Belinsky , Andrey K. Zhukovsky

While all bipartite pure entangled states violate some Bell inequality, the relationship between entanglement and non-locality for mixed quantum states is not well understood. We introduce a simple and efficient algorithmic approach for the…

Quantum Physics · Physics 2009-11-07 Barbara M. Terhal , Andrew C. Doherty , David Schwab

Strong quantum nonlocality was introduced recently as a stronger manifestation of nonlocality in multipartite systems through the notion of local irreducibility in all bipartitions. Known existence results for sets of strongly nonlocal…

Quantum Physics · Physics 2020-10-07 Fei Shi , Mengyao Hu , Lin Chen , Xiande Zhang

We present a new approach to the analysis of entanglement in smooth bipartite continuous-variable states. One or both parties perform projective filterings via preliminary measurements to determine whether the system is located in some…

Quantum Physics · Physics 2009-11-13 H. -C. Lin , A. J. Fisher

In the first part of this paper we analyze possible quantum computational capacities due to quantum queries associated with equi-partitions of pure orthogonal states. Special emphasis is given to the parity of product states and to…

Quantum Physics · Physics 2016-09-07 Karl Svozil

Understanding the relation between the different forms of inseparability in quantum mechanics is a longstanding problem in the foundations of quantum theory and has implications for quantum information processing. Here we make progress in…

Quantum Physics · Physics 2013-04-09 Daniel Cavalcanti , Antonio Acin , Nicolas Brunner , Tamas Vertesi

Non-locality without entanglement is a rather counter-intuitive phenomenon in which information may be encoded entirely in product (unentangled) states of composite quantum systems in such a way that local measurement of the subsystems is…

Quantum Physics · Physics 2017-03-08 Sarah Croke , Stephen M Barnett

We have studied the possibility of post-quantum theories more nonlocal than the (standard) quantum theory using the modification of the quantum probability rule under the no-signaling condition. For this purpose we have considered the…

Quantum Physics · Physics 2012-08-15 Yeong Deok Han , Taeseung Choi

Density matrices are the most general descriptions of quantum states, covering both pure and mixed states. Positive semidefiniteness is a physical requirement of density matrices, imposing nonnegative probabilities of measuring physical…

Quantum Physics · Physics 2024-09-11 Colm Kelleher

We revisit the properties of qubits under Lorentz transformations and, by considering Lorentz invariant quantum states in the Heisenberg formulation, clarify some misleading notation that has appeared in the literature on relativistic…

Quantum Physics · Physics 2017-04-26 Xavier Calmet , Jacob Dunningham

Motivated by Popescu's example of hidden nonlocality, we elaborate on the conjecture that quantum states that are intuitively nonlocal, i.e., entangled, do not admit a local causal hidden variables model. We exhibit quantum states which…

Quantum Physics · Physics 2009-10-30 Stefan Teufel , Karin Berndl , Detlef Dürr , Sheldon Goldstein , Nino Zangh\`ı

The nonlocal properties of the W states are investigated under particle loss. By removing all but two particles from an $N$-qubit W state, the resulting two-qubit state is still entangled. Hence, the W state has high persistency of…

Quantum Physics · Physics 2016-05-20 Péter Diviánszky , Réka Trencsényi , Erika Bene , Tamás Vértesi

Recently developed quantum algorithms suggest that quantum computers can solve certain problems and perform certain tasks more efficiently than conventional computers. Among other reasons, this is due to the possibility of creating…

Quantum Physics · Physics 2007-05-23 Rolando D. Somma

The (non-)local content in the sense of Elitzur, Popescu, and Rohrlich (EPR2) [Phys. Lett. A 162, 25 (1992)] is a natural measure for the (non-)locality of quantum states. Its computation is in general difficult, even in low dimensions, and…

Quantum Physics · Physics 2012-07-17 Samuel Portmann , Cyril Branciard , Nicolas Gisin

Several proposed quantum computer models include measurement processes, in order to implement nonlocal gates and create necessary entanglement resources during the computation. We introduce a scheme in which the measurements can be delayed…

Quantum Physics · Physics 2007-05-23 Daegene Song