9,790 research outputs found

    Entanglement and spin squeezing properties for three bosons in two modes

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    We discuss the canonical form for a pure state of three identical bosons in two modes, and classify its entanglement correlation into two types, the analogous GHZ and the W types as well known in a system of three distinguishable qubits. We have performed a detailed study of two important entanglement measures for such a system, the concurrence C\mathcal{C} and the triple entanglement measure τ\tau. We have also calculated explicitly the spin squeezing parameter ξ\xi and the result shows that the W state is the most ``anti-squeezing'' state, for which the spin squeezing parameter cannot be regarded as an entanglement measure.Comment: 7 pages, 6 figures; corrected figure sequence. Thanks to Dr. Han P

    N-qubit entanglement via the Jy2J_y^2-type collective interaction

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    We investigate quantum correlations of the NN-qubit states via a collective pseudo-spin interaction (Jy2\propto J_y^2) on arbitrary pure separable states for a given interval of time. Based on this dynamical generation of the NN-qubit maximal entangled states, a quantum secret sharing protocol with NN continuous classical secrets is developed.Comment: 12 pages, 3 figure

    Confidence and Backaction in the Quantum Filter Equation

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    We study the confidence and backaction of state reconstruction based on a continuous weak measurement and the quantum filter equation. As a physical example we use the traditional model of a double quantum dot being continuously monitored by a quantum point contact. We examine the confidence of the estimate of a state constructed from the measurement record, and the effect of backaction of that measurement on that state. Finally, in the case of general measurements we show that using the relative entropy as a measure of confidence allows us to define the lower bound on the confidence as a type of quantum discord.Comment: 9 pages, 6 figure

    Genetic differentiation in Japanese flounder in the Yellow Sea and East China Sea by amplified fragment length polymorphism (AFLP) and mitochondrial DNA markers

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    The population structure of Japanese flounder (Paralichthys olivaceus) in the Yellow and East China Seas were analyzed using amplified fragment length polymorphism (AFLP) and cytochrome c oxidase subunit I (COI) gene sequencing. A total of 390 reproducible bands were generated by 10 AFLP primer combinations in two populations collected from the coasts of Qingdao (located at the Yellow Sea) and Zhoushan (located at the East China Sea). The percentage of polymorphic loci (P), Nei’s genetic diversity (H) and Shannon’s information index (I) values were higher in the Qingdao population (P = 72.85%, H = 0.243 and I = 0.364) than those in the Zhoushan population (P = 56.35%, H = 0.189 and I = 0.284). The genetic diversity reduction in the Zhoushan population may be attributed to fishing pressure and habitat loss in this area. Based on the COI sequencing analysis, a total of 25 polymorphic sites were examined, and 15 haplotypes were identified in the two populations. The haplotype diversity (h) and nucleotide diversity (π) values in the Qingdao population were 0.746 ± 0.0728 and 0.00334 ± 0.00103, respectively. The corresponding values in the Zhoushan population were 0.712 ± 0.0470 and 0.00318 ± 0.00049. Both the AFLP and mtDNA data revealed significant genetic differentiation between the two populations. The present study discussed the factors that may result in genetic differentiation between the populations in the Yellow and East China Seas.Keywords: Japanese flounder, amplified fragment length polymorphism (AFLP), cytochrome c oxidase subunit I (COI) gene, genetic diversity, population structur

    Statistical experimental methods for optimizing the cultivating conditions for Rhodococcus erythropolis

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    Rhodococcus erythropolis was found to effectively degrade aflatoxin Bl produced by Aspergillus flavus and Aspergillus parasiticus. However, one problem of concern was the slow growth of this strain. In this study, Plackett–Burman design was used to select the most important variables, namely, temperature, pH, inoculum size, liquid volume, agitation speed and culture time that affected the growth of R. erythropolis. Central composite experimental design and response surface analysis were adopted to derive a statistical model for optimizing the culture conditions. From the obtained results, it can be concluded that the optimum parameters were: temperature, 15.3°C; pH, 5.56; inoculum size, 4%; liquid volume, 70 ml in 250 ml flask; agitation speed, 180 rpm; and culture time, 58.2 h. At this optimum point, the populations of the viable organisms could reach 108 colony forming units (CFU)/ml, which was 100 times higher than that incubated under the initial conditions. After 58.2 h incubation in this optimum cultivating conditions, 53.9 ± 2.1% of aflatoxin B1 was degraded, while only 20.6±1.4% of aflatoxin B1 was degraded in the initial conditions.Key words: Rhodococcus erythropolis, culture condition, optimization, Plackett–Burman design, central composite design, response surface methodology

    Soft Mode Dynamics Above and Below the Burns Temperature in the Relaxor Pb(Mg_1/3Nb_2/3)O_3

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    We report neutron inelastic scattering measurements of the lowest-energy transverse optic (TO) phonon branch in the relaxor Pb(Mg_1/3Nb_2/3)O_3 from 400 to 1100 K. Far above the Burns temperature T_d ~ 620 K we observe well-defined propagating TO modes at all wave vectors q, and a zone center TO mode that softens in a manner consistent with that of a ferroelectric soft mode. Below T_d the zone center TO mode is overdamped. This damping extends up to, but not above, the waterfall wave vector q_wf, which is a measure of the average size of the PNR.Comment: 4 pages, 4 figures; modified discussion of Fig. 3, shortened captions, added reference, corrected typos, accepted by Phys. Rev. Let

    Visual Affect Around the World: A Large-scale Multilingual Visual Sentiment Ontology

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    Every culture and language is unique. Our work expressly focuses on the uniqueness of culture and language in relation to human affect, specifically sentiment and emotion semantics, and how they manifest in social multimedia. We develop sets of sentiment- and emotion-polarized visual concepts by adapting semantic structures called adjective-noun pairs, originally introduced by Borth et al. (2013), but in a multilingual context. We propose a new language-dependent method for automatic discovery of these adjective-noun constructs. We show how this pipeline can be applied on a social multimedia platform for the creation of a large-scale multilingual visual sentiment concept ontology (MVSO). Unlike the flat structure in Borth et al. (2013), our unified ontology is organized hierarchically by multilingual clusters of visually detectable nouns and subclusters of emotionally biased versions of these nouns. In addition, we present an image-based prediction task to show how generalizable language-specific models are in a multilingual context. A new, publicly available dataset of >15.6K sentiment-biased visual concepts across 12 languages with language-specific detector banks, >7.36M images and their metadata is also released.Comment: 11 pages, to appear at ACM MM'1
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