133,701 research outputs found

    A Study of Anyon Statistics by Breit Hamiltonian Formalism

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    We study the anyon statistics of a 2+12 + 1 dimensional Maxwell-Chern-Simons (MCS) gauge theory by using a systemmetic metheod, the Breit Hamiltonian formalism.Comment: 25 pages, LATE

    Type I superconductivity in the Dirac semimetal PdTe2

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    The superconductor PdTe2_2 was recently classified as a Type II Dirac semimetal, and advocated to be an improved platform for topological superconductivity. Here we report magnetic and transport measurements conducted to determine the nature of the superconducting phase. Surprisingly, we find that PdTe2_2 is a Type I superconductor with Tc=1.64T_c = 1.64 K and a critical field Ό0Hc(0)=13.6\mu_0 H_c (0) = 13.6 mT. Our crystals also exhibit the intermediate state as demonstrated by the differential paramagnetic effect. For H>HcH > H_c we observe superconductivity of the surface sheath. This calls for a close examination of superconductivity in PdTe2_2 in view of the presence of topological surface states.Comment: 5 page

    Studying RFID adoption by SMES in the Taiwanese IT industry

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    With the advent of Radio Frequency Identification (RFID), organisations have the opportunity to rethink how their organisation will operate and integrate in the supply chain. Especially for Small to Medium Sized Enterprises (SMEs), that they have limited resources adopting such an innovative technology (i.e. RFID) can be daunting. Literature indicates that SMEs that deal with implementation have so far only a few guidelines regarding specific opportunities and risks. This research is therefore trying to fill the gap by employing Exploratory Factor Analysis (EFA) techniques and utilising a questionnaire survey with the aim of exploring the factors that affect SMEs’ RFID adoption in the Taiwan Information Technology (IT) manufacturing industry. In doing so, the adoption factors which are classified into 3 different adopters categories named ready adopter (cost and management), initiator adopter (competitiveness and process efficiency) and unprepared adopter (IT management difficulties, IT implementation difficulties and cost of implementation) using EFA technique. A SMEs RFID adoption model is then proposed. It is anticipated that the findings of this research will not only enhance the research in RFID adoption in SMEs, but can also act as a reference for practitioners in the industry and researchers in the academic field

    Analysis and interpretation of high transverse entanglement in optical parametric down conversion

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    Quantum entanglement associated with transverse wave vectors of down conversion photons is investigated based on the Schmidt decomposition method. We show that transverse entanglement involves two variables: orbital angular momentum and transverse frequency. We show that in the monochromatic limit high values of entanglement are closely controlled by a single parameter resulting from the competition between (transverse) momentum conservation and longitudinal phase matching. We examine the features of the Schmidt eigenmodes, and indicate how entanglement can be enhanced by suitable mode selection methods.Comment: 4 pages, 4 figure

    Direct simulation for a homogenous gas

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    A probabilistic analysis of the direct simulation of a homogeneous gas is given. A hierarchy of equations similar to the BBGKY hierarchy for the reduced probability densities is derived. By invoking the molecular chaos assumption, an equation similar to the Boltzmann equation for the single particle probability density and the corresponding H-theorem is derived

    Real time hand gesture recognition including hand segmentation and tracking

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    In this paper we present a system that performs automatic gesture recognition. The system consists of two main components: (i) A unified technique for segmentation and tracking of face and hands using a skin detection algorithm along with handling occlusion between skin objects to keep track of the status of the occluded parts. This is realized by combining 3 useful features, namely, color, motion and position. (ii) A static and dynamic gesture recognition system. Static gesture recognition is achieved using a robust hand shape classification, based on PCA subspaces, that is invariant to scale along with small translation and rotation transformations. Combining hand shape classification with position information and using DHMMs allows us to accomplish dynamic gesture recognition

    Periodic Modulation of Extraordinary Optical Transmission through Subwavelength Hole Arrays using Surrounding Bragg Mirrors

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    The enhanced light transmission through an array of subwavelength holes surrounded by Bragg mirrors is studied, showing that the mirrors act to confine the surface plasmons associated with the Extraordinary Optical Transmission effect, forming a surface resonant cavity. The overall effect is increased light transmission intensity by more than a factor of three beyond the already enhanced transmission, independent of whether the Bragg mirrors are on the input or the output side of the incident light. The geometry of the Bragg mirror structures controls the enhancement, and can even reduce the transmission in half. By varying these geometric parameters, we were able to periodically modulate the transmission of light for specific wavelengths, consistent with the propagation and interference of surface plasmon waves in a resonant cavity. FDTD simulations and a wave propagation model verify this effect.Comment: 9 pages, 5 figure

    Anomalous pressure effect on the magnetic ordering in multiferroic BiMnO3

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    We report the magnetic field dependent dc magnetization and the pressure-dependent (pmax ~ 16 kbar) ac susceptibilities Xp(T) on both powder and bulk multiferroic BiMnO3 samples, synthesized in different batches under high pressure. A clear ferromagnetic (FM) transition is observed at TC ~ 100 K, and increases with magnetic field. The magnetic hysteresis behavior is similar to that of a soft ferromagnet. Ac susceptibility data indicate that both the FM peak and its temperature (TC) decrease simultaneously with increasing pressure. Interestingly, above a certain pressure (9 ~ 11 kbar), another peak appears at Tp ~ 93 K, which also decreases with increasing pressure, with both these peaks persisting over some intermediate pressure range (9 ~ 13 kbar). The FM peak disappears with further application of pressure; however, the second peak survives until present pressure limit (pmax ~ 16 kbar). These features are considered to originate from the complex interplay of the magnetic and orbital structure of BiMnO3 being affected by pressure.Comment: 4 pages,4 figures, publised in Physical Review B 78, 092404/200

    Muon spin rotation study of the topological superconductor SrxBi2Se3

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    We report transverse-field (TF) muon spin rotation experiments on single crystals of the topological superconductor Srx_xBi2_2Se3_3 with nominal concentrations x=0.15x=0.15 and 0.180.18 (Tc∌3T_c \sim 3 K). The TF spectra (B=10B= 10 mT), measured after cooling to below TcT_c in field, did not show any additional damping of the muon precession signal due to the flux line lattice within the experimental uncertainty. This puts a lower bound on the magnetic penetration depth λ≄2.3 Ό\lambda \geq 2.3 ~\mum. However, when we induce disorder in the vortex lattice by changing the magnetic field below TcT_c a sizeable damping rate is obtained for T→0T \rightarrow 0. The data provide microscopic evidence for a superconducting volume fraction of ∌70 %\sim 70~ \% in the x=0.18x=0.18 crystal and thus bulk superconductivity.Comment: 6 pages, includes 4 figure

    From insulator to quantum Hall liquid at low magnetic fields

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    We have performed low-temperature transport measurements on a GaAs two-dimensional electron system at low magnetic fields. Multiple temperature-independent points and accompanying oscillations are observed in the longitudinal resistivity between the low-field insulator and the quantum Hall (QH) liquid. Our results support the existence of an intermediate regime, where the amplitudes of magneto-oscillations can be well described by conventional Shubnikov-de Haas theory, between the low-field insulator and QH liquid.Comment: Magneto-oscillations governed by Shubnikov-de Haas theory are observed between the low-field insulator and quantum Hall liqui
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