2,354 research outputs found
Influences of an impurity on the transport properties of one-dimensional antisymmetric spin filter
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
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
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 -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
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
atoms for Yb with a trap density of cm 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
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
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
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
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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