English
Related papers

Related papers: Projective measurements are sufficient for recycli…

200 papers

We define nonlocal predictability as how well one observer can predict another's measurement outcomes without classical communication, given full knowledge of the shared quantum state and measurement settings. The local bound on nonlocal…

Quantum Physics · Physics 2026-02-19 Chirag Srivastava , Aparajita Bhattacharyya , Ujjwal Sen

Relativity theory severely restricts the ability to perform nonlocal measurements in quantum mechanics. Studying such nonlocal schemes may thus reveal insights regarding the relations between these two fundamental theories. Therefore, for…

Quantum repeaters can overcome exponential photon loss in optical fibers, enabling heralded entanglement between distant quantum memories. The definitive benchmark for this entanglement is Bell nonlocality; however, recent…

Relativistic causality has dramatic consequences on the measurability of nonlocal variables and poses the fundamental question of whether it is physically meaningful to speak about the value of nonlocal variables at a particular time.…

Quantum Physics · Physics 2014-11-20 S. R. Clark , A. J. Connor , D. Jaksch , S. Popescu

Quantum nonlocality is usually associated with entangled states by their violations of Bell-type inequalities. However, even unentangled systems, whose parts may have been prepared separately, can show nonlocal properties. In particular, a…

Quantum Physics · Physics 2019-02-06 Saronath Halder , Manik Banik , Sristy Agrawal , Somshubhro Bandyopadhyay

Nonlocality and quantum entanglement constitute two special aspects of the quantum correlations existing in quantum systems, which are of paramount importance in quantum-information theory. Traditionally, they have been regarded as…

Quantum Physics · Physics 2015-05-27 J. Batle , M. Casas

The study of quantum nonlocality sharing has garnered significant attention, particularly for two-qubit and three-qubit entangled systems. In this paper, we extend the investigation to $n$-qubit Greenberger-Horne-Zeilinger (GHZ) systems,…

Quantum Physics · Physics 2025-08-12 Sk Sahadat Hossain , Indrani Chattopadhyay

We introduce measurement-based quantum repeaters, where small-scale measurement-based quantum processors are used to perform entanglement purification and entanglement swapping in a long-range quantum communication protocol. In the scheme,…

Quantum Physics · Physics 2013-06-03 M. Zwerger , W. Dür , H. J. Briegel

Bell inequalities are an important tool in device-independent quantum information processing because their violation can serve as a certificate of relevant quantum properties. Probably the best known example of a Bell inequality is due to…

There is no doubt about the fact that entanglement and nonlocality are distinct resources. It is acknowledged that a clear illustration of this point is the difference between maximally entangled states and states that maximally violate a…

Quantum Physics · Physics 2015-09-23 E. A. Fonseca , Fernando Parisio

Quantum nonlocality and contextuality are two phenomena stemming from nonclassical correlations. Whereas the former requires entanglement that is consumed in the measurement process the latter can occur for any state if one chooses a proper…

Quantum Physics · Physics 2016-05-11 Marek Wajs , Su-Yong Lee , Pawel Kurzynski , Dagomir Kaszlikowski

One of the most fascinating aspects of quantum networks is their capability to distribute entanglement as a nonlocal communication resource. In a first step, this requires network-ready devices that can generate and store entangled states.…

Lately, much interest has been directed towards designing setups that achieve decisive tests of local realism. Here we present Bell tests with measurements based on linear optical displacements and single-photon detection. The scheme…

Quantum Physics · Physics 2013-01-25 Jonatan Bohr Brask , Rafael Chaves

We have applied an entanglement purification protocol to produce a single entangled pair of photons capable of violating a CHSH Bell inequality from two pairs that individually could not. The initial poorly-entangled photons were created by…

Quantum Physics · Physics 2009-11-11 P. Walther , K. J. Resch , C. Brukner , A. M. Steinberg , J. -W. Pan , A. Zeilinger

Although entanglement is necessary for observing nonlocality in a Bell experiment, there are entangled states which can never be used to demonstrate nonlocal correlations. In a seminal paper [PRL 108, 200401 (2012)] F. Buscemi extended the…

Quantum Physics · Physics 2021-04-07 Patryk Lipka-Bartosik , Andrés Ducuara , Tom Purves , Paul Skrzypczyk

Quantum Bell nonlocality is an important quantum phenomenon. Recently, the shareability of Bell nonlocality under unilateral measurements has been widely studied. In this study, we consider the shareability of quantum Bell nonlocality under…

Quantum Physics · Physics 2022-10-27 Tinggui Zhang , Qiming Luo , Xiaofen Huang

In this paper, we investigate the critical efficiency of detectors to observe Bell nonlocality using multiple copies of the maximally entangled two-qubit state carried by a single pair of particles, such as hyperentangled states, and the…

Quantum Physics · Physics 2023-02-09 István Márton , Erika Bene , Tamás Vértesi

To date, most efforts to demonstrate quantum nonlocality have concentrated on systems of two (or very few) particles. It is however difficult in many experiments to address individual particles, making it hard to highlight the presence of…

We experimentally demonstrate the nonlocal reversal of a partial-collapse quantum measurement on two-photon entangled state. Both the partial measurement and the reversal operation are implemented in linear optics with two displaced Sagnac…

Quantum Physics · Physics 2015-05-20 Xiao-Ye Xu , Jin-Shi Xu , Chuan-Feng Li , Yang Zou , Guang-Can Guo

Given a bipartite quantum state rho with subsystems A and B of arbitrary dimensions, we study the entanglement detecting capabilities of locally noneffective, or cyclic, unitary operations [L. B. Fu, Europhys. Lett., vol. 75, pp. 1-7,…

Quantum Physics · Physics 2009-12-21 Sevag Gharibian , Hermann Kampermann , Dagmar Bruss