11,470 research outputs found
Lattice-coupled Antiferromagnet on Frustrated Lattices
Lattice-coupled antiferromagnetic spin model is analyzed for a number of
frustrated lattices: triangular, Kagome, and pyrochlore. In triangular and
Kagome lattices where ground state spins are locally ordered, the spin-lattice
interaction does not lead to a static deformation of the lattice. In the
pyrochlore structure, spin-lattice coupling supports a picture of the hexagon
spin cluster proposed in the recent experiment[S. H. Lee et al. Nature, 418,
856 (2002)]. Through spin-lattice interaction a uniform contraction of the
individual hexagons in the pyrochlore lattice can take place and reduce the
exchange energy. Residual hexagon-hexagon interaction takes the form of a
3-states Potts model where the preferred directions of the spin-loop directors
for nearby hexagons are mutually orthogonal
Neural Sequence-to-grid Module for Learning Symbolic Rules
Logical reasoning tasks over symbols, such as learning arithmetic operations
and computer program evaluations, have become challenges to deep learning. In
particular, even state-of-the-art neural networks fail to achieve
\textit{out-of-distribution} (OOD) generalization of symbolic reasoning tasks,
whereas humans can easily extend learned symbolic rules. To resolve this
difficulty, we propose a neural sequence-to-grid (seq2grid) module, an input
preprocessor that automatically segments and aligns an input sequence into a
grid. As our module outputs a grid via a novel differentiable mapping, any
neural network structure taking a grid input, such as ResNet or TextCNN, can be
jointly trained with our module in an end-to-end fashion. Extensive experiments
show that neural networks having our module as an input preprocessor achieve
OOD generalization on various arithmetic and algorithmic problems including
number sequence prediction problems, algebraic word problems, and computer
program evaluation problems while other state-of-the-art sequence transduction
models cannot. Moreover, we verify that our module enhances TextCNN to solve
the bAbI QA tasks without external memory.Comment: 9 pages, 9 figures, AAAI 202
Singlet Fermionic Dark Matter with Dark
We present a fermionic dark matter model mediated by the hidden gauge boson.
We assume the QED-like hidden sector which consists of a Dirac fermion and
U(1) gauge symmetry, and introduce an additional scalar electroweak doublet
field with the U(1) charge as a mediator. The hidden U(1) symmetry is
spontaneously broken by the electroweak symmetry breaking and there exists a
massive extra neutral gauge boson in this model which is the mediator between
the hidden and visible sectors. Due to the U(1) charge, the additional
scalar doublet does not couple to the Standard Model fermions, which leads to
the Higgs sector of type I two Higgs doublet model. The new gauge boson couples
to the Standard Model fermions with couplings proportional to those of the
ordinary boson but very suppressed, thus we call it the dark boson. We
study the phenomenology of the dark boson and the Higgs sector, and show
the hidden fermion can be the dark matter candidate.Comment: 10 pages, 3 figure
Contextual Linear Bandits under Noisy Features: Towards Bayesian Oracles
We study contextual linear bandit problems under uncertainty on features;
they are noisy with missing entries. To address the challenges from the noise,
we analyze Bayesian oracles given observed noisy features. Our Bayesian
analysis finds that the optimal hypothesis can be far from the underlying
realizability function, depending on noise characteristics, which is highly
non-intuitive and does not occur for classical noiseless setups. This implies
that classical approaches cannot guarantee a non-trivial regret bound. We thus
propose an algorithm aiming at the Bayesian oracle from observed information
under this model, achieving regret bound with respect to
feature dimension and time horizon . We demonstrate the proposed
algorithm using synthetic and real-world datasets.Comment: 30 page
Potassium-doped BaFe2As2 superconducting thin films with a transition temperature of 40 K
We report the growth of potassium-doped BaFe2As2 thin films, where the major
charge carriers are holes, on Al2O3 (0001) and LaAlO3 (001) substrates by using
an ex-situ pulsed laser deposition technique. The measured Tc's are 40 and 39 K
for the films grown on Al2O3 and LaAlO3, respectively and diamagnetism
indicates that the films have good bulk superconducting properties below 36 and
30 K, respectively. The X-ray diffraction patterns for both films indicated a
preferred c-axis orientation, regardless of the substrate structures of LaAlO3
and Al2O3. The upper critical field at zero temperature was estimated to be
about 155 T.Comment: 6 pages including 3 figure
K-pop Lyric Translation: Dataset, Analysis, and Neural-Modelling
Lyric translation, a field studied for over a century, is now attracting
computational linguistics researchers. We identified two limitations in
previous studies. Firstly, lyric translation studies have predominantly focused
on Western genres and languages, with no previous study centering on K-pop
despite its popularity. Second, the field of lyric translation suffers from a
lack of publicly available datasets; to the best of our knowledge, no such
dataset exists. To broaden the scope of genres and languages in lyric
translation studies, we introduce a novel singable lyric translation dataset,
approximately 89\% of which consists of K-pop song lyrics. This dataset aligns
Korean and English lyrics line-by-line and section-by-section. We leveraged
this dataset to unveil unique characteristics of K-pop lyric translation,
distinguishing it from other extensively studied genres, and to construct a
neural lyric translation model, thereby underscoring the importance of a
dedicated dataset for singable lyric translations
In-situ fabrication of cobalt-doped SrFe2As2 thin films by using pulsed laser deposition with excimer laser
The remarkably high superconducting transition temperature and upper critical
field of iron(Fe)-based layered superconductors, despite ferromagnetic material
base, open the prospect for superconducting electronics. However, success in
superconducting electronics has been limited because of difficulties in
fabricating high-quality thin films. We report the growth of high-quality
c-axis-oriented cobalt(Co)-doped SrFe2As2 thin films with bulk
superconductivity by using an in-situ pulsed laser deposition technique with a
248-nm-wavelength KrF excimer laser and an arsenic(As)-rich phase target. The
temperature and field dependences of the magnetization showing strong
diamagnetism and transport critical current density with superior Jc-H
performance are reported. These results provide necessary information for
practical applications of Fe-based superconductors.Comment: 8 pages, 3figures. to be published at Appl. Phys. Let
- …