A. Shafiee, R. Maleeh, M. Golshani
Considering the common cause principle, we construct a local-contextual hidden-variable model for the Bohm version of EPR experiment. Our proposed model can reproduce the predictions of quantum mechanics. It can be also extended to classical examples in which similar correlations may be revealed.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
Trade-off relations between Bell nonlocality and local Kochen-Specker contextuality in generalized Bell scenarios
本文研究广义贝尔场景中贝尔非定域性与局域科亨-斯佩克语境相关性的关系，证明二者可共存但存在数量权衡，并从不等式、量化器及全局语境相关性概念展开分析，还指出该概念涵盖其他非经典关联。
Bell non-locality and Kochen-Specker (KS) contextuality are logically independent concepts, fuel different protocols with quantum vs classical advantage, and have distinct classical simulation costs. A natural question is what are the relations between these concepts, advantages, and costs. To address this question, it is useful to have a map that captures all the connections between Bell non-locality and KS contextuality in quantum theory. The aim of this work is to introduce such a map. After defining the theory-independent notions of Bell non-locality and KS contextuality for ideal measurem…
An invertible map between Bell non-local and contextuality scenarios
本文构造了贝尔非局域性与情境性场景之间的可逆映射，并借此证明量子情境行为集合的成员资格问题不可判定、无法由有限维量子系统完全实现且非闭集。
Kupczynski's Contextual Locally Causal Probabilistic Models are constrained by Bell's theorem
本文证明 Kupczynski 的语境化局部因果概率模型仍属于 Bell 局域隐变量模型，无法规避 Bell-CHSH 不等式，其论证实质上依赖已被无漏洞实验封闭的探测漏洞。
We highlight the existence of a joint probability distribution as the common underpinning assumption behind Bell-type, contextuality, and Leggett-Garg-type tests. We then present a procedure to translate contextual scenarios into temporal Leggett-Garg-type and spatial Bell-type ones. To demonstrate the generality of this approach we construct a family of spatial Bell-type inequalities. We show that in Leggett-Garg scenario a necessary condition for contextuality in time is given by a violation of consistency conditions in Consistent Histories approach to quantum mechanics.
Efficient teleportation is a crucial step for quantum computation and quantum networking. In the case of qubits, four different entangled Bell states have to be distinguished. We have realized a probabilistic, but in principle deterministic, Bell-state analyzer for two photonic quantum bits by the use of a nondestructive controlled-NOT gate based on entirely linear optical elements. This gate was capable of distinguishing between all of the Bell states with higher than 75% fidelity without any noise substraction due to utilizing quantum interference effects.
Global Kochen-Specker Contextuality Without Local Contextuality and Generalized Bell Nonlocality
本文提出全局语境性概念，通过三组二分体构造证明，即使局部统计非语境且每个多体语境允许广义局部隐变量描述，整体系统仍可能不存在单一非语境隐变量模型。
Revealing hidden nonlocality and preparation contextuality for an arbitrary input Bell inequality
该研究利用局域滤波操作，基于PORAC博弈对应的Bell泛函，证明不同n阈值下任意非零混合参数的混合纠缠态可分别激活隐藏非定域性与制备互文性。
We discuss the problem of hidden variables and the motivation for introducting them in quantum mechanics. These include determinism, and the problem of meassurement and incompleteness. We first discuss Von-Neumann's imposisbility proof and then analyse it's weakness in terms of Bell's explicit hidden variable model of spin one-half particles. We next discuss Gleason's theorem and Kochen-Specker theorem and bring out the troublems with non contextual hidden variable theories. An important role is played by Einstein locality in the discussion of hidden variable theories as was first brought out …
We show how Bell observables on a bipartite quantum system can be obtained by local observables via a controlled-unitary transformation. For continuous variables this result holds for the Bell observable corresponding to the non-conventional heterodyne measurement on two radiation modes, which is connected through a 50-50 beam-splitter to two local observables given by single-mode homodyne measurements. A simple scheme for a controlled-unitary transformation of continuous variables is also presented, which needs only two squeezers, a parametric downconverter and two beam splitters.
An Entanglement Monotone from the Contextual Fraction
本文提出基于情境分数的纠缠单调性度量QTCF，证明2量子比特态在依赖状态的Bell场景下其情境分数为纠缠单调性，并给出保证情境性所需最小纠缠熵的上界约0.601。
We analyze the linear optical realization of number-sum Bell measurement and number-state manipulation by taking into account the realistic experimental situation, specifically imperfectness of single-photon detector. The present scheme for number-state manipulation is based on the number-sum Bell measurement, which is implemented with linear optical elements, i.e., beam splitters, phase shifters and zero-one-photon detectors. Squeezed vacuum states and coherent states are used as optical sources. The linear optical Bell state detector is formulated quantum theoretically with a probability ope…
The Bell-KS theorem and the more recent $ψ$-epistemic \emph{no-go} theorems of QM are discussed in the context of Entropic Dynamics. In doing so we find that the Bell-KS theorem allows for, a perhaps overlooked, hybrid-contextual model of QM in which one set of commuting observables (position in this case) is non-contextual and all other observables are contextual. Entropic Dynamics is in a unique position as compared to other foundational theories of QM because it derives QM using standard techniques in Bayesian probability theory. In this formalism, position is the preferred basis from which…
Response: Kupczynski Contextual Locally Causal Probabilistic Models are constrained by Bell theorem
本文回应指出，Kupczynski的语境化局部因果概率模型因违反统计独立性而声称不受Bell定理约束，但实验数据违反非信号性表明其逃逸路线不可用，标题与结论具有误导性。
A unified framework for Bell inequalities from continuous-variable contextuality
本文提出一个统一框架，用于研究连续变量情境下的贝尔不等式，发现无法映射到CHSH不等式的连续变量非局域性示例，并提供混合DV-CV纠缠态的实例。
Contextuality and entanglement are valuable resources for quantum computing and quantum information. Bell inequalities are used to certify entanglement; thus, it is important to understand why and how they are violated. Quantum mechanics and behavioral sciences teach us that random variables measuring the same content (the answer to the same Yes or No question) may vary, if measured jointly with other random variables. Alice and Bob raw data confirm Einsteinian non-signaling, but setting dependent experimental protocols are used to create samples of coupled pairs of distant outcomes and to est…
Here, we consider the Bell experiment for a system described by multipartite states in the case where n-dichotomic observables are measured per site. If n is two, we consider a two-setting Bell experiment. If n is three, we consider a three-setting Bell experiment. Twosetting model is an explicit local realistic model for the values of a correlation function, given in a two-setting Bell experiment. Three-setting model is an explicit local realistic model for the values of a correlation function, given in a three-setting Bell experiment. In the non-contextual scenario, there is not the differen…
A unified view on the phenomenon of monogamy exhibited by Bell inequalities and non-contextuality inequalities arising from the no-signaling and no-disturbance principles is presented using the graph-theoretic method introduced in \textit{Phys. Rev. Lett. 109, 050404 (2012)}. We propose a novel type of trade-off, namely Bell inequalities that do not exhibit monogamy features of their own can be activated to be monogamous by the addition of a local contextuality term. This is illustrated by means of the well-known $\mathcal{I}_{3322}$ inequality, and reveals a resource trade-off between biparti…
A simultaneous realization of the Universal Optimal Quantum Cloning Machine (UOQCM) and of the Universal-NOT gate by a quantum injected optical parametric amplification (QIOPA), is reported. The two processes, forbidden in their exact form for fundamental quantum limitations, are found universal and optimal, and the measured fidelity F<1 is found close to the limit values evaluated by quantum theory. This work may enlighten the yet little explored interconnections of fundamental axiomatic properties within the deep structure of quantum mechanics.
We question the commonly accepted statement that random numbers certified by Bell's theorem carry some special sort of randomness, so to say, quantum randomness or intrinsic randomness. We show that such numbers can be easily generated by classical random generators.
We construct a non-contextual hidden variable model consistent with all the kinematic predictions of quantum mechanics (QM). The famous Bell-KS theorem shows that non-contextual models which satisfy a further reasonable restriction are inconsistent with QM. In our construction, we define a weaker variant of this restriction which captures its essence while still allowing a non-contextual description of QM. This is in contrast to the contextual hidden variable toy models, such as the one by Bell, and brings out an interesting alternate way of looking at QM. The results also relate to the Bohmia…
A scheme for distributed quantum measurement that allows nondestructive or indirect Bell measurement was proposed by Gupta et al., (Int. J. Quant. Infor. \textbf{5} (2007) 627) and subsequently realized experimentally using an NMR-based three-qubit quantum computer by Samal et al., (J. Phys. B, \textbf{43} (2010) 095508). In the present work, a similar experiment is performed using the five-qubit super-conductivity-based quantum computer, which has been recently placed in cloud by IBM Corporation. The experiment confirmed that the Bell state can be constructed and measured in a nondestructive …
A violation of Bell-CHSH inequalities does not justify speculations about quantum non-locality, conspiracy and retro-causation. Such speculations are rooted in a belief that setting dependence of hidden variables in a probabilistic model, called a violation of measurement independence, would mean a violation of experimenters freedom of choice. This belief is unfounded because it is based on a questionable use of Bayes Theorem and on incorrect causal interpretation of conditional probabilities. In Bell-local realistic model, hidden variables describe only photonic beams created by a source, thu…
It is currently widely accepted, as a result of Bell's theorem and related experiments, that quantum mechanics is inconsistent with local realism and there is the so called quantum non-locality. We show that such a claim can be justified only in a simplified approach to quantum mechanics when one neglects the fundamental fact that there exist space and time. Mathematical definitions of local realism in the sense of Bell and in the sense of Einstein are given. We demonstrate that if we include into the quantum mechanical formalism the space-time structure in the standard way then quantum mechan…
Proposed experiments for detecting contextual hidden variables
受流体力学导波系统启发，提出两项改进Bell测试实验以探测量子力学背后的contextual hidden variables，并论证此类理论能以local且non-conspiratorial的方式绕过Bell's theorem。
The derivation of Bell inequalities for beables is well-known to require a "no-conspiracy" assumption. This assumption is widely accepted, the alternative being correlations between instrument settings and hidden beables. Two further assumptions are identified here: (1) a "no-contextuality" assumption, similar to the prohibition of contextuality that is required to derive the Kochen-Specker theorem, which is closely related to the "no-conspiracy" assumption; (2) a "no-correlation" assumption, which prohibits correlations between hidden beables. The three assumptions together are less acceptabl…
Tests are essential in Information Retrieval and Data Mining in order to evaluate the effectiveness of a query. An automatic measure tool intended to exhibit the meaning of words in context has been developed and linked with Quantum Theory, particularly entanglement. "Quantum like" experiments were undertaken on semantic space based on the Hyperspace Analogue Language (HAL) method. A quantum HAL model was implemented using state vectors issued from the HAL matrix and query observables, testing a wide range of windows sizes. The Bell parameter S, associating measures on two words in a document,…
We present the experimental realization of the optimal estimation protocol for a Pauli noisy channel. The method is based on the generation of 2-qubit Bell states and the introduction of quantum noise in a controlled way on one of the state subsystems. The efficiency of the optimal estimation, achieved by a Bell measurement, is shown to outperform quantum process tomography.
An extended Wigner's friend no-go theorem inspired by generalized contextuality
本文基于非局部性证明与广义情境性证明的对应关系，提出非情境性朋友无矛盾定理，证明量子理论与绝对观测事件和非情境性代理联合假设不一致，扩展了局部朋友无矛盾定理。
Operational Discriminability: From Noncontextuality Bounds to Bell Correlations
本文通过基于SWAP型测量的两复制比较游戏，从操作和上下文性角度研究判别性，提出了一种无需最小误差判别任务的操作判别度量，并探讨了其在非上下文性和贝尔相关性中的应用。
Cyclic systems of dichotomous random variables have played a prominent role in contextuality research, describing such experimental paradigms as the Klyachko-Can-Binicoglu-Shumovky, Einstein-Podolsky-Rosen-Bell, and Leggett-Garg ones in physics, as well as conjoint binary choices in human decision making. Here, we understand contextuality within the framework of the Contextuality-by-Default (CbD) theory, based on the notion of probabilistic couplings satisfying certain constraints. CbD allows us to drop the commonly made assumption that systems of random variables are consistently connected. C…
In quantum physics, the notion of contextuality has a variety of interpretations which are typically associated with the names of their inventors, say Bohr, Bell, Kochen and Specker, and recently Dzhafarov. In fact, Bohr was the first who pointed to contextuality of quantum measurements as a part of formulation of his principle of complementarity. (Instead of "contextuality", he considered dependence on "experimental conditions.") Unfortunately, the contextuality counterpart of the complementarity principle was overshadowed by the issue of incompatibility of observables. And the interest for c…
Generalized Bell scenarios: disturbing consequences on local-hidden-variable models
本文在Bell非定域性与Kochen-Specker情境性的统一框架下，探讨了局域模型内部的情境性与扰动特征，定义了不同局域集合，揭示了量子与后量子关联行为，并扩展了Fine-Abramsky-Brandenburger定理。
Considering an extended type of Bohm's version of EPR thought experiment, we derive Bell's inequality for the case of factorizable contextual hidden variable theories which are consistent with the predictions of quantum theory. Usually factorizability is associated with non-contextuality. Here, we show that factorizability is consistent with contextuality, even for the ordinary Bohm's version of EPR thought experiment.
In a couple of recent preprints Moldoveanu has suggested that there are errors in my disproof of Bell's theorem. Here I show that this claim is false. In particular, I show that my local-realistic framework is incorrectly and misleadingly presented in both of his preprints. In addition there are a number of serious mathematical and conceptual errors in his discussion of my framework. For example, contrary to his claim, my framework is manifestly non-contextual. In particular, quantum correlations are understood within it as purely topological effects, not contextual effects.
Monogamy relations of entropic non-contextual inequalities and their experimental realization
本文基于图论方法建立理论框架，分析熵非上下文性不等式的单配性关系，证明两个熵Bell-CHSH不等式在三方场景下具有单配性，并通过NMR量子信息处理器实验验证，且实验仅需测量可观测量期望值。
Extendability of an empirical model was shown by Abramsky & Brandenburger to correspond in a unified manner to both locality and non-contextuality. We develop their approach by presenting a refinement of the notion of extendability that can also be useful in characterising the properties of sub-models. The refinement is found to have another useful application: it is shown that a particular canonical extension, when well-defined, may be used for the construction of Bell-type models from models of more general kinds in such a way that the constructed model is equivalent to the original in terms…
The Kochen-Specker theorem, Bell inequalities, and several other tests that were designed to rule out hidden-variable theories, assume the existence of observables having infinitely sharp eigenvalues. A paradigmatic example is spin-1/2. It is measured with a Stern-Gerlach array whose outputs are divided into two classes, spin-up and spin-down, in correspondence to the two spots observed on a detection screen. The spot's finite size is attributed to imperfections of the measuring device. This assumption turns the experimental output into a dichotomic, discrete one, thereby allowing the assignme…
A simultaneous, contextual experimental demonstration of the two processes of cloning an input qubit and of flipping it into the orthogonal qubit is reported. The adopted experimental apparatus, a Quantum-Injected Optical Parametric Amplifier (QIOPA) is transformed simultaneously into a Universal Optimal Quantum Cloning Machine (UOQCM) and into a Universal NOT quantum-information gate. The two processes, indeed forbidden in their exact form for fundamental quantum limitations, will be found to be universal and optimal, i.e. the measured fidelity of both processes F<1 will be found close to the…
In quantum physics the term `contextual' can be used in more than one way. One usage, here called `Bell contextual' since the idea goes back to Bell, is that if $A$, $B$ and $C$ are three quantum observables, with $A$ compatible (i.e., commuting) with $B$ and also with $C$, whereas $B$ and $C$ are incompatible, a measurement of $A$ might yield a different result (indicating that quantum mechanics is contextual) depending upon whether $A$ is measured along with $B$ (the $\{A,B\}$ context) or with $C$ (the $\{A,C\}$ context). An analysis of what projective quantum measurements measure shows that…
The probabilistic structure of quantum mechanics is investigated in the frequency framework. Such an approach can be interpreted as a contextual approach to quantum probabilities. By using rather complicated frequency calculations we reproduce the EPR-Bohm correlation function which is typically derived by using the calculus of probabilities in a Hilbert space. Our frequency probabilistic model of the EPR-Bohm experiment is a realist model -- physical observables are considered as objective properties of physical systems. It is also local -- a measurement over one part of a composite system do…
Contextuality and correlation loopholes are equivalent
本文证明包含测量设备效应的语境隐变量可通过格林函数向后传播至初始柯西隐数据，在类空不相交集合不相关时可推导出CHSH-Bell不等式，但关联漏洞仍未闭合。
Bell inequalities may only be derived, if hidden variables do not depend on the experimental settings. The stochastic independence of hidden and setting variables is called: freedom of choice, free will, measurement independence or no conspiracy. By imbedding the Bell causal structure in a larger causal network the authors correctly prove, that one can explain and quantify possible violation of measurement independence without evoking the super-determinism. They assume the independence of the variables that causally determine the settings and investigate how they might become correlated with h…
John Bell taught us that quantum mechanics can not be reproduced by non-contextual and local Hidden variable theory. The impossibility of replacing quantum mechanics by non-contextual Hidden Variable Theory can be turned to a impossible coloring pseudo-telepathy game to be played by two distant players. The game can not be won without communication in the classical world. But if the players share entangled state (quantum correlation) the game can be won deterministically using no communication. This again shows that though quantum correlation can not be used for communication, two parties can …
Contextuality means non-existence of a joint distribution for random variables recorded under mutually incompatible conditions, subject to certain constraints imposed on how the identity of these variables may change across these conditions. In simple quantum systems contextuality is indicated by violations of Bell-type or Leggett-Garg-type inequalities. These inequalities, however, are predicated on the assumption of no-signaling, defined as invariance of the distributions of measurement results with respect to other (e.g., earlier in time) measurements' settings. Signaling makes the inequali…
On the applicability of Kolmogorov's theory of probability to the description of quantum phenomena. Part II: Bell inequalities
本文从柯尔莫哥洛夫概率论视角分析贝尔不等式，提出并研究贝尔实验中的语境性概念，证明一类情境模型满足BCHSH不等式，但强局域性下仍可违反，揭示常见物理结论的概念误解。
We prove that the action of the Yangian algebra Y(sl_N) is better described by the principal generators on the tensor product of the fundamental representation and its dual. The generalized Bell states or maximally entangled states are permuted by the principal generators in a dramatically simple manner on the tensor product. Under the Yangian symmetry the new quantum number J^2 is also explicitly computed, which gives an explanation for these maximally entangled states.
When Bertlmann wears no socks. Common causes induced by measurements as an explanation for quantum correlations
本文重访 Bertlmann 的袜子例子，提出由测量过程语境性诱导并在每次联合测量中现实化的共同原因，可解释关联为何能违反 Bell 不等式。
We address the problem of deriving the set of quantum correlations for every Bell and Kochen-Specker (KS) contextuality scenario from simple assumptions. We show that the correlations that are possible according to quantum theory are equal to those possible under the assumptions that there is a nonempty set of correlations for every KS scenario and a statistically independent realization of any two KS experiments. The proof uses tools of the graph-theoretic approach to correlations and deals with Bell nonlocality and KS contextuality in a unified way.
Quantum mechanics can produce correlations that are stronger than classically allowed. This stronger-than-classical correlation is the "fuel" for quantum computing. In 1991 Schumacher forwarded a beautiful geometric approach, analogous to the well-known result of Bell, to capture non-classicality of this correlation for a singlet state. He used well-established information distance defined on an ensemble of identically-prepared states. He calculated that for certain detector settings used to measure the entangled state, the resulting geometry violated a triangle inequality -- a violation that …
We report on the experimental realization of two different Bell inequality tests based on six-qubit linear-type and Y-shape graph states. For each of these states, the Bell inequalities tested are optimal in the sense that they provide the maximum violation among all Bell inequalities with stabilizing observables and possess the maximum resistance to noise.
Single-measurement Bell analysis
本文通过联合噪声测量分析量子系统单次实现的贝尔准则，发现所有结果均违反局部隐变量界限，表明非经典测量方案是揭示非经典效应的必要条件。
Probe of Generic Quantum Contextuality and Nonlocal Resources for Qubits
本文通过量子记忆的熵不确定性关系，揭示了Spekkens提出的本地通用情境性与非本地资源如纠缠和贝尔非本地性之间的内在联系，并通过实验验证了情境性检测准则和定量不等式。
Quantum mechanics provides a statistical description about nature, and thus would be incomplete if its statistical predictions could not be accounted for some realistic models with hidden variables. There are, however, two powerful theorems against the hidden-variable theories showing that certain quantum features cannot be reproduced based on two rationale premises of classicality, the Bell theorem, and noncontextuality, due to Bell, Kochen and Specker (BKS) . Tests of the Bell inequality and the BKS theorem are both of fundamental interests and of great significance . The Bell theorem has al…
It is shown that the Bell inequalities are closely related to the triangle inequalities involving distance functions amongst pairs of random variables with values $\left\{ 0,1\right\} $. A hidden variables model may be defined as a mapping between a set of quantum projection operators and a set of random variables. The model is noncontextual if there is a joint probability distribution. The Bell inequalities are necessary conditions for its existence. The inequalities are most relevant when measurements are performed at space-like separation, thus showing a conflict between quantum mechanics a…
We study the faces of the set of quantum correlations, i.e., the Bell and noncontextuality inequalities without any quantum violation. First, we investigate the question whether every proper (tight) Bell inequality for two parties, other than the trivial ones from positivity, normalization and no-signaling can be violated by quantum correlations, i.e., whether the classical Bell polytope or the smaller correlation polytope share any facets with their respective quantum sets. To do this, we develop a recently derived bound on the quantum value of linear games based on the norms of game matrices…
The Bell-type (spatial), Kochen-Specker (contextuality) or Leggett-Garg (temporal) inequalities are based on classically plausible but otherwise quite distinct assumptions. For any of these inequalities, satisfaction is equivalent to a joint probability distribution for all observables in the experiment. This implies a joint distribution for all pairs of observables, and is indifferent to whether or not they commute in the theory. This indifference underpins a unification of the above inequalities into a general framework of correlation inequalities. When the physical scenario is such that the…
By filtering out the philosophic component we can be said that the EPR-paper was directed against the straightforward interpretation of the Heisenberg's uncertainty principle or more generally the Bohr's complementarity principle. The latter expresses contextuality of quantum measurements: dependence of measurement's output on the complete experimental arrangement. However, Bell restructured the EPR-argument against complementarity to justify nonlocal theories with hidden variables of the Bohmian mechanics' type. Then this Bell's kind of nonlocality - {\it subquantum nonlocality} - was lifted …
Automated generation of photonic circuits for Bell tests with homodyne measurements
本文提出自动化框架，利用深度强化学习和量子光学模拟设计光子电路，实现显著违反CHSH不等式的贝尔测试实验。
We present an optical implementation of two programmable quantum measurement devices. The first one serves for unambiguous discrimination of two nonorthogonal states of a qubit. The particular pair of states to be discriminated is specified by the quantum state of a program qubit. The second device can perform von Neumann measurements on a single qubit in any basis located on the equator of the Bloch sphere. Again, the basis is selected by the state of a program qubit. In both cases the data and program qubits are represented by polarization states of photons. The experimental apparatus exploi…
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。