2,354 research outputs found

    Influences of an impurity on the transport properties of one-dimensional antisymmetric spin filter

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    The influences of an impurity on the spin and the charge transport of one-dimensional antisymmetric spin filter are investigated using bosonization and Keldysh formulation and the results are highlighted against those of spinful Luttinger liquids. Due to the dependence of the electron spin orientation on wave number the spin transport is not affected by the impurity, while the charge transport is essentially identical with that of spinless one-dimensional Luttinger liquid.Comment: 7 pages, 2 figures. To appear in Physical Review

    Surface Normal Estimation of Tilted Images via Spatial Rectifier

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    In this paper, we present a spatial rectifier to estimate surface normals of tilted images. Tilted images are of particular interest as more visual data are captured by arbitrarily oriented sensors such as body-/robot-mounted cameras. Existing approaches exhibit bounded performance on predicting surface normals because they were trained using gravity-aligned images. Our two main hypotheses are: (1) visual scene layout is indicative of the gravity direction; and (2) not all surfaces are equally represented by a learned estimator due to the structured distribution of the training data, thus, there exists a transformation for each tilted image that is more responsive to the learned estimator than others. We design a spatial rectifier that is learned to transform the surface normal distribution of a tilted image to the rectified one that matches the gravity-aligned training data distribution. Along with the spatial rectifier, we propose a novel truncated angular loss that offers a stronger gradient at smaller angular errors and robustness to outliers. The resulting estimator outperforms the state-of-the-art methods including data augmentation baselines not only on ScanNet and NYUv2 but also on a new dataset called Tilt-RGBD that includes considerable roll and pitch camera motion.Comment: 16 page

    Microscopic Theory of Rashba Interaction in Magnetic Metal

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    Theory of Rashba spin-orbit coupling in magnetic metals is worked out from microscopic Hamiltonian describing d-orbitals. When structural inversion symmetry is broken, electron hopping between dd-orbitals generates chiral ordering of orbital angular momentum, which combines with atomic spin-orbit coupling to result in the Rashba interaction. Rashba parameter characterizing the interaction is band-specific, even reversing its sign from band to band. Large enhancement of the Rashba parameter found in recent experiments is attributed to the orbital mixing of 3d magnetic atoms with non-magnetic heavy elements as we demonstrate by first-principles and tight-binding calculations.Comment: 5 pages, 2 figure

    Efficient magneto-optical trapping of Yb atoms with a violet laser diode

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    We report the first efficient trapping of rare-earth Yb atoms with a high-power violet laser diode (LD). An injection-locked violet LD with a 25 mW frequency-stabilized output was used for the magneto-optical trapping (MOT) of fermionic as well as bosonic Yb isotopes. A typical number of 4×1064\times 10^6 atoms for 174^{174}Yb with a trap density of 1×108/\sim 1\times10^8/cm3^3 was obtained. A 10 mW violet external-cavity LD (ECLD) was used for the one-dimensional (1D) slowing of an effusive Yb atomic beam without a Zeeman slower resulting in a 35-fold increase in the number of trapped atoms. The overall characteristics of our compact violet MOT, e.g., the loss time of 1 s, the loading time of 400 ms, and the cloud temperature of 0.7 mK, are comparable to those in previously reported violet Yb MOTs, yet with a greatly reduced cost and complexity of the experiment.Comment: 5 pages, 3 figures, 1 table, Phys. Rev. A (to be published

    Cinnamaldehyde enhances in vitro parameters of immunity and reduces in vivo infection against avian coccidiosis

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    The effects of cinnamaldehyde (CINN) on in vitro parameters of immunity and in vivo protection against avian coccidiosis were evaluated. In vitro stimulation of chicken spleen lymphocytes with CINN (25-400ng/ml) induced greater cell proliferation compared with the medium control (P<0·001). CINN activated cultured macrophages to produce higher levels of NO at 1·2-5·0μg/ml (P<0·001), inhibited the growth of chicken tumour cells at 0·6-2·5μg/ml (P<0·001) and reduced the viability of Eimeria tenella parasites at 10 and 100μg/ml (P<0·05 and P<0·001, respectively), compared with media controls. In chickens fed a diet supplemented with CINN at 14·4mg/kg, the levels of IL-1β, IL-6, IL-15 and interferon-γ transcripts in intestinal lymphocytes were 2- to 47-fold higher (P<0·001) compared with chickens given a non-supplemented diet. To determine the effect of CINN diets on avian coccidiosis, chickens were fed diets supplemented with CINN at 14·4mg/kg (E. maxima or E. tenella) or 125mg/kg (E. acervulina) from hatch for 24d, and orally infected with 2·0×104 sporulated oocysts at age 14d. CINN-fed chickens showed 16·5 and 41·6% increased body-weight gains between 0-9d post-infection (DPI) with E. acervulina or E. maxima, reduced E. acervulina oocyst shedding between 5-9 DPI and increased E. tenella-stimulated parasite antibody responses at 9 DPI compared with control

    Superfield theory and supermatrix model

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    We study the noncommutative superspace of arbitrary dimensions in a systematic way. Superfield theories on a noncommutative superspace can be formulated in two folds, through the star product formalism and in terms of the supermatrices. We elaborate the duality between them by constructing the isomorphism explicitly and relating the superspace integrations of the star product Lagrangian or the superpotential to the traces of the supermatrices. We show there exists an interesting fine tuned commutative limit where the duality can be still maintained. Namely on the commutative superspace too, there exists a supermatrix model description for the superfield theory. We interpret the result in the context of the wave particle duality. The dual particles for the superfields in even and odd spacetime dimensions are D-instantons and D0-branes respectively to be consistent with the T-duality.Comment: 1+16 pages, no figure; expanded version, references added; Convention for Clifford algebra improve

    Superconformal Yang-Mills quantum mechanics and Calogero model with OSp(N|2,R) symmetry

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    In spacetime dimension two, pure Yang-Mills possesses no physical degrees of freedom, and consequently it admits a supersymmetric extension to couple to an arbitrary number, N say, of Majorana-Weyl gauginos. This results in (N,0) super Yang-Mills. Further, its dimensional reduction to mechanics doubles the number of supersymmetries, from N to N+N, to include conformal supercharges, and leads to a superconformal Yang-Mills quantum mechanics with symmetry group OSp(N|2,R). We comment on its connection to AdS_2 \times S^{N-1} and reduction to a supersymmetric Calogero model.Comment: 1+28 pages, no figure; Refs added. To appear in JHE

    AdS and pp-wave D-particle superalgebras

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    We derive anticommutators of supercharges with a brane charge for a D-particle in AdS(2) x S(2) and pp-wave backgrounds. A coset GL(2|2)/(GL(1))^4 and its Penrose limit are used with the supermatrix-valued coordinates for the AdS and the pp-wave spaces respectively. The brane charges have position dependence, and can be absorbed into bosonic generators by shift of momenta which results in closure of the superalgebras.Comment: 15 page
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