2,515 research outputs found

    Quantum entanglement, unitary braid representation and Temperley-Lieb algebra

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    Important developments in fault-tolerant quantum computation using the braiding of anyons have placed the theory of braid groups at the very foundation of topological quantum computing. Furthermore, the realization by Kauffman and Lomonaco that a specific braiding operator from the solution of the Yang-Baxter equation, namely the Bell matrix, is universal implies that in principle all quantum gates can be constructed from braiding operators together with single qubit gates. In this paper we present a new class of braiding operators from the Temperley-Lieb algebra that generalizes the Bell matrix to multi-qubit systems, thus unifying the Hadamard and Bell matrices within the same framework. Unlike previous braiding operators, these new operators generate {\it directly}, from separable basis states, important entangled states such as the generalized Greenberger-Horne-Zeilinger states, cluster-like states, and other states with varying degrees of entanglement.Comment: 5 pages, no figur

    Teleportation, Braid Group and Temperley--Lieb Algebra

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    We explore algebraic and topological structures underlying the quantum teleportation phenomena by applying the braid group and Temperley--Lieb algebra. We realize the braid teleportation configuration, teleportation swapping and virtual braid representation in the standard description of the teleportation. We devise diagrammatic rules for quantum circuits involving maximally entangled states and apply them to three sorts of descriptions of the teleportation: the transfer operator, quantum measurements and characteristic equations, and further propose the Temperley--Lieb algebra under local unitary transformations to be a mathematical structure underlying the teleportation. We compare our diagrammatical approach with two known recipes to the quantum information flow: the teleportation topology and strongly compact closed category, in order to explain our diagrammatic rules to be a natural diagrammatic language for the teleportation.Comment: 33 pages, 19 figures, latex. The present article is a short version of the preprint, quant-ph/0601050, which includes details of calculation, more topics such as topological diagrammatical operations and entanglement swapping, and calls the Temperley--Lieb category for the collection of all the Temperley--Lieb algebra with physical operations like local unitary transformation

    Self-organized Networks of Competing Boolean Agents

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    A model of Boolean agents competing in a market is presented where each agent bases his action on information obtained from a small group of other agents. The agents play a competitive game that rewards those in the minority. After a long time interval, the poorest player's strategy is changed randomly, and the process is repeated. Eventually the network evolves to a stationary but intermittent state where random mutation of the worst strategy can change the behavior of the entire network, often causing a switch in the dynamics between attractors of vastly different lengths.Comment: 4 pages, 3 included figures. Some text revision and one new figure added. To appear in PR

    Quantum Algebras Associated With Bell States

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    The antisymmetric solution of the braided Yang--Baxter equation called the Bell matrix becomes interesting in quantum information theory because it can generate all Bell states from product states. In this paper, we study the quantum algebra through the FRT construction of the Bell matrix. In its four dimensional representations via the coproduct of its two dimensional representations, we find algebraic structures including a composition series and a direct sum of its two dimensional representations to characterize this quantum algebra. We also present the quantum algebra using the FRT construction of Yang--Baxterization of the Bell matrix.Comment: v1: 15 pages, 2 figures, latex; v2: 18 pages, 2 figures, latex, references and notes adde

    Maximum Power Efficiency and Criticality in Random Boolean Networks

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    Random Boolean networks are models of disordered causal systems that can occur in cells and the biosphere. These are open thermodynamic systems exhibiting a flow of energy that is dissipated at a finite rate. Life does work to acquire more energy, then uses the available energy it has gained to perform more work. It is plausible that natural selection has optimized many biological systems for power efficiency: useful power generated per unit fuel. In this letter we begin to investigate these questions for random Boolean networks using Landauer's erasure principle, which defines a minimum entropy cost for bit erasure. We show that critical Boolean networks maximize available power efficiency, which requires that the system have a finite displacement from equilibrium. Our initial results may extend to more realistic models for cells and ecosystems.Comment: 4 pages RevTeX, 1 figure in .eps format. Comments welcome, v2: minor clarifications added, conclusions unchanged. v3: paper rewritten to clarify it; conclusions unchange

    Fever of Unknown Origin in the Elderly: Lymphoma Presenting as Vertebral Compression Fractures

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111209/1/j.1532-5415.1994.tb06080.x.pd

    Coronavirus disease (Covid-19): psychoeducational variables involved in the health emergency

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    This monograph has allowed us to present a psychoeducational view of the effects of the COVID-19 pandemic. We confirm here that research in education contributes its own evidence and specific models for identifying this problem

    Noise, Synchrony and Correlations at the Edge of Chaos

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    We study the effect of a weak random additive noise in a linear chain of N locally-coupled logistic maps at the edge of chaos. Maps tend to synchronize for a strong enough coupling, but if a weak noise is added, very intermittent fluctuations in the returns time series are observed. This intermittency tends to disappear when noise is increased. Considering the pdfs of the returns, we observe the emergence of fat tails which can be satisfactorily reproduced by qq-Gaussians curves typical of nonextensive statistical mechanics. Interoccurrence times of these extreme events are also studied in detail. Similarities with recent analysis of financial data are also discussed.Comment: 6 pages, 8 figures, new figure added - Version accepted for publication in Physical Review

    Influence of misonidazole on the incidence of radiation-induced intestinal tumours in mice.

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    C57BL mice were given local irradiation to 2 cm2 of the lower abdomen in the dose range 16--24 Gy. There were some early deaths, but mice dying between 50--240 days predominantly developed invasive adenocarcinomas of the intestine. When the radiosensitizer misonidazole was given in a single dose shortly before irradiation the proportion of mice developing tumours was higher, but the difference was not statistically significant. However, there was a significant increase in the incidence of multiple tumours, largely attributable to tumours arising in the rectum

    Associations of Psychological Inflexibility with Exercise Self-Efficacy and Fatigue Severity among Individuals Seeking Treatment for Weight-Related Behaviors

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    Rates of obesity are continuing to rise, contributing to several negative health outcomes and economic burden. Past work suggests that individuals with greater body mass index (BMI) are more likely to report feeling fatigue and are less likely to follow an exercise regimen, which may lead to weight-related problems. Psychological inflexibility, a rigid thinking style in which individuals attempt to over-control psychological reactions to discomfort, may be an underrecognized explanatory factor underlying greater fatigue and lower rates of exercise among individuals with weight-related concerns. The aim of the current study was to explore the relationship between psychological inflexibility and both exercise self-efficacy and fatigue severity among adults seeking treatment for weight-related behaviors. The current study is a secondary analysis and included 162 treatment-seeking adults who attended a baseline appointment for a larger randomized-controlled trial for weight-related behaviors. Results indicated that greater psychological inflexibility was significantly related to greater fatigue severity and lower exercise self-efficacy. These results provide initial empirical evidence that psychological inflexibility may be an important individual difference factor in terms of fatigue and exercise beliefs among adults seeking treatment for weight-related behaviors
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