13,932 research outputs found

    Multilayer Graphene Synthesized by CVD Using Liquid Hexane as the Carbon Precursor

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    We produce multilayer graphene by the Chemical Vapor Deposition (CVD) method at atmospheric pressure and 1000 {\deg}C, using flexible copper substrates as catalyst and liquid hexane as the source of carbon. We designed an optical device to measure the transmittance of the carbon films; with this information we calculate that the approximate number of layers is 11.Comment: 6 pages, 5 figures. Accepted for publication in World Journal of Condensed Matter Physic

    Resource costs for fault-tolerant linear optical quantum computing

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    Linear optical quantum computing (LOQC) seems attractively simple: information is borne entirely by light and processed by components such as beam splitters, phase shifters and detectors. However this very simplicity leads to limitations, such as the lack of deterministic entangling operations, which are compensated for by using substantial hardware overheads. Here we quantify the resource costs for full scale LOQC by proposing a specific protocol based on the surface code. With the caveat that our protocol can be further optimised, we report that the required number of physical components is at least five orders of magnitude greater than in comparable matter-based systems. Moreover the resource requirements grow higher if the per-component photon loss rate is worse than one in a thousand, or the per-component noise rate is worse than 10−510^{-5}. We identify the performance of switches in the network as the single most influential factor influencing resource scaling

    MOND as the weak-field limit of an extended metric theory of gravity

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    We show that the Modified Newtonian Dynamics (MOND) regime can be fully recovered as the weak-field limit of a particular theory of gravity formulated in the metric approach. This is possible when Milgrom's acceleration constant is taken as a fundamental quantity which couples to the theory in a very consistent manner. As a consequence, the scale invariance of the gravitational interaction is naturally broken. In this sense, Newtonian gravity is the weak-field limit of general relativity and MOND is the weak-field limit of that particular extended theory of gravity.Comment: To appear in the proceedings of the 2011 Spanish Relativity Meeting (ERE2011) held in Madrid, Spain, 4 page
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