780 research outputs found

    Contextual, Optimal and Universal Realization of the Quantum Cloning Machine and of the NOT gate

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    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.Comment: 10 pages, 2 figure

    Modern ‘live’ football: moving from the panoptican gaze to the performative, virtual and carnivalesque

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    Drawing on Redhead's discussion of Baudrillard as a theorist of hyperreality, the paper considers the different ways in which the mediatized ‘live’ football spectacle is often modelled on the ‘live’ however eventually usurps the ‘live’ forms position in the cultural economy, thus beginning to replicate the mediatized ‘live’. The blurring of the ‘live’ and ‘real’ through an accelerated mediatization of football allows the formation of an imagined community mobilized by the working class whilst mediated through the sanitization, selling of ‘events’ and the middle classing of football, through the re-encoding of sporting spaces and strategic decision-making about broadcasting. A culture of pub supporting then allows potential for working-class supporters to remove themselves from the panoptican gazing systems of late modern hyperreal football stadia and into carnivalesque performative spaces, which in many cases are hyperreal and simulated themselves

    Classification of local realistic theories

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    Recently, it has shown that an explicit local realistic model for the values of a correlation function, given in a two-setting Bell experiment (two-setting model), works only for the specific set of settings in the given experiment, but cannot construct a local realistic model for the values of a correlation function, given in a {\it continuous-infinite} settings Bell experiment (infinite-setting model), even though there exist two-setting models for all directions in space. Hence, two-setting model does not have the property which infinite-setting model has. Here, we show that an explicit two-setting model cannot construct a local realistic model for the values of a correlation function, given in a {\it only discrete-three} settings Bell experiment (three-setting model), even though there exist two-setting models for the three measurement directions chosen in the given three-setting experiment. Hence, two-setting model does not have the property which three-setting model has.Comment: To appear in Journal of Physics A: Mathematical and Theoretica

    Hyperentangled States

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    We investigate a new class of entangled states, which we call 'hyperentangled',that have EPR correlations identical to those in the vacuum state of a relativistic quantum field. We show that whenever hyperentangled states exist in any quantum theory, they are dense in its state space. We also give prescriptions for constructing hyperentangled states that involve an arbitrarily large collection of systems.Comment: 23 pages, LaTeX, Submitted to Physical Review

    Randomness, Nonlocality and information in entagled correlations

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    It is shown that the Einstein, Podolsky and Rosen (EPR) correlations for arbitrary spin-s and the Greenberger, Horne and Zeilinger (GHZ) correlations for three particles can be described by nonlocal joint and conditional quantum probabilities. The nonlocality of these probabilities makes the Bell's inequalities void. A description that exhibits the relation between the randomness and the nonlocality of entangled correlations is introduced. Entangled EPR and GHZ correlations are studied using the Gibbs-Shannon entropy. The nonlocal character of the EPR correlations is tested using the information Bell's inequalities. Relations between the randomness, the nonlocality and the entropic information for the EPR and the GHZ correlations are established and discussed.Comment: 19 pages, REVTEX, 8 figures included in the uuencoded postscript fil

    Proposed direct test of a certain type of noncontextuality in quantum mechanics

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    The noncontextuality of quantum mechanics can be directly tested by measuring two entangled particles with more than two outcomes per particle. The two associated contexts are "interlinked" by common observables.Comment: 9 pages 2 figure

    On relativistic elements of reality

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    Several arguments have been proposed some years ago, attempting to prove the impossibility of defining Lorentz-invariant elements of reality. I find that a sufficient condition for the existence of elements of reality, introduced in these proofs, seems to be used also as a necessary condition. I argue that Lorentz-invariant elements of reality can be defined but, as Vaidman pointed out, they won't satisfy the so-called product rule. In so doing I obtain algebraic constraints on elements of reality associated with a maximal set of commuting Hermitian operators.Comment: Clarifications, reference added; published versio
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