In this Comment we show that Cabello's argument [Phys. Rev. Lett. 86, 1911 (2001)] which proves the nonlocal feature of any classical model of quantum mechanics based on Einstein-Podolsky-Rosen (EPR) criterion of elements of reality, must involve at least four distant observers rather than the two employed by the author. Moreover we raise a remark on the necessity of performing a real experiment confirming Cabello's argument.
We show that it is possible to have arbitrarily long sequences of Alices and Bobs so every (Alice, Bob) pair violates a Bell inequality. We propose an experiment to observe this effect with two Alices and two Bobs.
Reply to Comment on ``Proposal for the Measurement of Bell-Type Correlations from Continuous Variables''
最近K。巴纳谢克岛A. Walmsley，K. Wodkiewicz（quant-ph/0012097）评论了我们关于从连续变量测量钟型相关性的建议[T. C. Ralph，W. J. Munro，R. E. S. Polkinghorne，Phys. Rev. Lett. 85，2035（2000）]。他们的评论是基于对我们信件的公然误读和误解，因此是完全错误的。
This study points out a semi-quantum protocol for private comparison using Bell states (SQPC) suffering from the double C-NOT attack and the malicious agent attack. The attacker can easily obtain information through these attacks. An improved protocol is proposed, which can effectively resist both of these attacks.
There is currently much interest in the recycling of entangled systems, for use in quantum information protocols by sequential observers. In this work, we study the sequential generation of Bell nonlocality via recycling one or both components of two-qubit states. We first give a description of two-valued qubit measurements in terms of measurement bias, strength, and reversibility, and derive useful tradeoff relations between them. Then, we derive one-sided monogamy relations for unbiased observables, that strengthen the recent Conjecture in [S. Cheng {\it et al.}, Phys. Rev. A \textbf{104}, L…
Stronger two-observer all-versus-nothing violation of local realism
我们引入了一个两个观察者的全对无的贝尔定理的证明，它减少了所需的量子预测的数量从9 [A。Cabello，Phys. Rev. Lett. 87，010403（2001）; Z.- B. Chen等人，物理修订版信函90，160408（2003）]到4，提供了大量的证据反对当地的现实主义，降低了检测效率的要求，一个决定性的实验测试贝尔定理，并导致贝尔不等式类似Mermin不等式三个观察者[N. D. Mermin，Phys. Rev. Lett. 65，1838（1990）]，但只需要两个观察员。
In a recent article (Found Sci (2020) https://doi.org/10.1007/s10699-020-09666-0) Marek Czachor claims that the Bell inequality cannot be proved because variables of complementary measurements cannot be added or multiplied. Even though he has correctly identified the problems existing with the orthodox interpretation of the Bell inequality and dealt with them in an original way, the interpretation he addresses do not pertain to the original formulation given by John Stewart Bell.
Contrary to what Lambare [arXiv:2008.00369] assumes, in non-Newtonian calculus (a calculus based on non-Diophantine arithmetic) an integral is typically given by a nonlinear map. This is the technical reason why all the standard proofs of Bell-type inequalities fail if non-Newtonian hidden variables are taken into account. From the non-Newtonian perspective, Bell's inequality is a property of a limited and unphysical class of hidden-variable models. An explicit counterexample to Bell's theorem can be easily constructed.
Comment on "Proposal for the Measurement of Bell-Type Correlations from Continuous Variables"
在最近的一篇论文[T。C. Ralph，W. J. Munro，R. E. S. Polkinghorne，Phys. Rev. Lett. 85，2035（2000）]，作者提出了一个测试贝尔不等式的正交测量相关参数源的基础上。我们在这里提出了一个本地隐藏变量模型，再现所有的期望值预测所描述的实验方案，并指出，该建议是基于不一致的使用贝尔不等式。
Comment on 'Improving the security of protocols of quantum key agreement solely using Bell states and Bell measurement'
设计一个量子密钥协商（QKA）协议一直是一个具有挑战性的任务，因为它必须同时考虑安全性和公平性。最近，Zhu等人（Quantum Inf Process 14（11）：4245-4254）指出，Shukla等人的QKA协议（Quantum Inf Process 13（11）：2391-2405）存在一些安全缺陷（导致参与者攻击）。此外，他们还提出了一项改进措施，以避免这些缺点。然而，该研究指出，改进的协议也遭受共谋攻击，即，协议中的两个不诚实的参与者可以合作来操纵最终密钥而不被发现。
Bell nonlocality plays a fundamental role in quantum theory. Numerous tests of the Bell inequality have been reported since the ground-breaking discovery of the Bell theorem.Up to now, however, most discussions of the Bell scenario have focused on a single pair of entangled particles distributed to only two separated observers. Recently, it has been shown surprisingly that multiple observers can share the nonlocality present in a single particle from an entangled pair using the method of weak measurements [Phys. Rev. Lett. {\bf 114}, 250401 (2015)]. Here we report an observation of double CHSH…
Comment on "Cosmic Bell Test: Measurement Settings from Milky Way Stars"
本文认为，在[J.Handsteiner et al.，物理修订版信函118，060401（2017）]和其他地方，实际上遵循更基本的前提。度量的独立性来自于（i）自由变量的使用和（ii）时间的因果箭头。决定论来自（i）局部因果关系和（ii）完美的相关性（由量子力学预测）。特别指出[M.J.W. Hall，Phys. Rev. Lett. 105，250404（2010）]基于追溯因果模型。虽然这可能是有争议的，但应该有可能在贝尔定理的基本假设是什么这一更简单的问题上达成共识。
Decoherence is an unavoidable phenomenon that results from the interaction of the system with its surroundings. The study of decoherence due to the relativistic effects has the fundamental importance. The Unruh effect is observed by the relativistically accelerator observer. The unruh effect acts as a quantum channel and we call it the Unruh Channel. The Unruh channel can be characterize by providing its Kraus representation. We consider the bipartite scheme in which the quantum information is shared between an inertial observer (Alice) and an accelerated observer (Rob) in the case of Dirac fi…
The purpose of this comment is to show that a reinterpretation of the results from the Letter: "Physics and Metaphysics of Wigner's Friends: Even performed pre-measurements have no results" allows for reaching the conclusion "pre-measurements have no resul" [arXiv:2003.07464] based only on postulates of quantum mechanics without additional assumptions on irreversibility. Additionally, with supplementary reasoning based on Bell's theorem, one can show that unitary decoherence cannot be solely responsible for the quantum-to-classical transition, and an additional irreversibility model is require…
In a recent interesting article Chris Nagele, Ebubechukwu O. IloOkeke, Peter P. Rohde, Jonathan P. Dowling, and Tim Byrnes discuss an entanglement swapping experiment using a setup where it is possible to switch the time ordering of measurements. I would like to draw your attention to the fact that the very same idea was introduced in two previous papers, and briefly address some important points related to the subject.
We give strong analytic and numerical evidence that, under mild measurement assumptions, two qubits cannot both be recycled to generate Bell nonlocality between multiple independent observers on each side. This is surprising, as under the same assumptions it is possible to recycle just one of the qubits an arbitrarily large number of times [P. J. Brown and R. Colbeck, Phys. Rev. Lett. 125, 090401 (2020)]. We derive corresponding 'one-sided monogamy relations' that rule out two-sided recycling for a wide range of parameters, based on a general tradeoff relation between the strengths and maximum…
I point out critical errors in the paper "Bell's Theorem Versus Local Realism in a Quaternionic Model of Physical Space" by J. Christian, published in IEEE Access. Christian's paper in fact contains several conflicting models. None of them form counterexamples to Bell's theorem. Most of Christian's paper is devoted to a model based on the detection loophole due to Pearle (1970).
Comment on "Significant-Loophole-Free Test of Bell's Theorem with Entangled Photons"
在最近的一篇文章中，Giustina等人[Phys. Rev. Lett. 115，250401（2015）]报告了一个先进的贝尔实验，同时关闭了局部隐变量理论的漏洞。作者声称，“本地现实主义”已被驳斥，除非“真正的异国情调的假设”。在这里，我认为，一个特别广泛和自然类的本地隐变量理论生存，例如，当隐变量描述的背景场。这种基于背景的理论利用了选择自由的漏洞，对于这种类型的隐藏变量，这个漏洞是无法关闭的。这种模型的动力学可以通过现有的系统来说明，例如来自流体力学。
