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Related papers: Parameter Dependence and Bell nonlocality

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Simultaneous estimation of multiple parameters in quantum metrological models is complicated by factors relating to the (i) existence of a single probe state allowing for optimal sensitivity for all parameters of interest, (ii) existence of…

Quantum Physics · Physics 2019-02-01 Sammy Ragy , Marcin Jarzyna , Rafal Demkowicz-Dobrzanski

Reviewing the general representation of a stochastic local hidden variables theory in the context of an ideal Bohm's version of the EPR experiment, we show explicitly that the violation of Bell's locality condition is due to the assumption…

Quantum Physics · Physics 2007-05-23 Afshin Shafiee , Mehdi Golshani

Bell's theorem is purported to demonstrate the impossibility of a local "hidden variable" theory underpinning quantum mechanics. It relies on the well-known assumption of `locality', and also on a little-examined assumption called…

Quantum Physics · Physics 2017-07-12 Steven Weinstein

Certifying maximal quantum randomness without assumptions about system dimension remains a pivotal challenge for secure communication and foundational studies. Here, we introduce a generalized framework to directly certify maximal…

Quantum Physics · Physics 2025-07-15 Tianqi Zheng , Yi Li , Yu Xiang , Qiongyi He

Given a pair of isolated devices that accept random binary inputs and return binary outputs, a user can deduce from the observed data alone if the underlying mechanism can be explained classically. Bell's theorem further states that a…

Quantum Physics · Physics 2026-05-21 Kuntal Sengupta , Lewis Wooltorton

In the derivation of local bound of a Bell's inequality, the response functions corresponding to the different outcomes of measurements are fixed by the relevant hidden variables irrespective of the fact if the measurement is unsharp. In…

Quantum Physics · Physics 2018-06-05 Asmita Kumari , A. K. Pan

In the experimental verification of Bell's inequalities in real photonic experiments, it is generally believed that the so-called fair sampling assumption (which means that a small fraction of results provide a fair statistical sample) has…

Quantum Physics · Physics 2007-05-23 Afshin Shafiee , Mehdi Golshani

To obtain Bell statistics from hybrid systems composed of finite- and infinite-dimensional systems, we propose a hybrid measurement scheme, in which the continuous mode is measured using the generalized pseudospin operators, while the…

Quantum Physics · Physics 2025-02-26 Pritam Halder , Ratul Banerjee , Saptarshi Roy , Aditi Sen De

The Bell inequalities stand at the cornerstone of the developments of quantum theory on both the foundational and applied side. The discussion started as a way to test whether the quantum description of reality is complete or not, but it…

Quantum Physics · Physics 2023-02-14 Nicolas Gigena , Giovanni Scala , Antonio Mandarino

Bell correlations are usually formulated for an ideal spin singlet, for which the Bell--CHSH combination reaches the maximal quantum value \(B=-2\sqrt{2}\), independent of detector separation. Here we derive Bell correlations from a more…

Quantum Physics · Physics 2026-05-26 Ju Gao , Fang Shen

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

For linear combinations of quantum product averages in an arbitrary bipartite state, we derive new quantum Bell-form and CHSH-form inequalities with the right-hand sides expressed in terms of a bipartite state. This allows us to specify in…

Quantum Physics · Physics 2011-01-04 Elena R. Loubenets

It has been believed that statistical inequality such as Bell inequality should be modified once measurement independence (MI), the assumption that observers can freely choose measurement settings without changing the probability…

Quantum Physics · Physics 2014-03-19 Minsu Kim , Jinhyoung Lee , Sang Wook Kim

Nonlocality as a fundamental aspect of quantum mechanics is witnessed by violation of Bell inequality or its variants, for which all relevant studies assume some correlations exhibited by local realistic theories. The strategy of Bell's…

Quantum Physics · Physics 2020-12-04 Boya Xie , Sheng Feng

We investigate quantum parameter estimation based on linear and Kerr-type nonlinear controls in an open quantum system, and consider the dissipation rate as an unknown parameter. We show that while the precision of parameter estimation is…

Quantum Physics · Physics 2017-12-12 Beili Gong , Wei Cui

The performance of the Quantum Approximate Optimisation Algorithm (QAOA) relies on the setting of optimal parameters in each layer of the circuit. This is no trivial task, and much literature has focused on the challenge of finding optimal…

Quantum Physics · Physics 2024-02-14 Vivek Katial , Kate Smith-Miles , Charles Hill

We study multipartite Bell nonlocality in a framework native of multipartite Einstein-Podolsky-Rosen (EPR) steering scenarios with a single trusted measurement device. We derive a closed-form necessary and sufficient criterion for systems…

Quantum Physics · Physics 2016-09-14 M. M. Taddei , R. V. Nery , L. Aolita

According to quantum theory, the outcomes obtained by measuring an entangled state necessarily exhibit some randomness if they violate a Bell inequality. In particular, a maximal violation of the CHSH inequality guarantees that 1.23 bits of…

Quantum Physics · Physics 2012-03-23 Antonio Acin , Serge Massar , Stefano Pironio

The two-particle correlation obtained from the quantum state used in the Bell inequality is sinusoidal, but the standard Bell inequality only uses two pairs of settings and not the whole sinusoidal curve. The highest to-date visibility of…

Quantum Physics · Physics 2022-03-16 Marek Zukowski , Dagomir Kaszlikowski , Adam Baturo , Jan-Åke Larsson

We discuss Bell nonlocality in quantum networks with unreliable sources. Our main result is a condition on the observed data which ensures that inconclusive events can be safely discarded, without introducing any loophole. More formally, we…

Quantum Physics · Physics 2025-12-11 Sadra Boreiri , Nicolas Brunner , Pavel Sekatski