22,284 research outputs found
Highly efficient source for frequency-entangled photon pairs generated in a 3rd order periodically poled MgO-doped stoichiometric LiTaO3 crystal
We present a highly efficient source for discrete frequency-entangled photon
pairs based on spontaneous parametric down-conversion using 3rd order type-0
quasi-phase matching in a periodically poled MgO-doped stoichiometric LiTaO3
crystal pumped by a 355.66 nm laser. Correlated two-photon states were
generated with automatic conservation of energy and momentum in two given
spatial modes. These states have a wide spectral range, even under small
variations in crystal temperature, which consequently results in higher
discreteness. Frequency entanglement was confirmed by measuring two-photon
quantum interference fringes without any spectral filtering.Comment: 4 pages, 4 figures, to be published in Optics Letter
Distinctive-attribute Extraction for Image Captioning
Image captioning, an open research issue, has been evolved with the progress
of deep neural networks. Convolutional neural networks (CNNs) and recurrent
neural networks (RNNs) are employed to compute image features and generate
natural language descriptions in the research. In previous works, a caption
involving semantic description can be generated by applying additional
information into the RNNs. In this approach, we propose a distinctive-attribute
extraction (DaE) which explicitly encourages significant meanings to generate
an accurate caption describing the overall meaning of the image with their
unique situation. Specifically, the captions of training images are analyzed by
term frequency-inverse document frequency (TF-IDF), and the analyzed semantic
information is trained to extract distinctive-attributes for inferring
captions. The proposed scheme is evaluated on a challenge data, and it improves
an objective performance while describing images in more detail.Comment: 14 main pages, 4 supplementary page
Dynamical mean-field theory of Hubbard-Holstein model at half-filling: Zero temperature metal-insulator and insulator-insulator transitions
We study the Hubbard-Holstein model, which includes both the
electron-electron and electron-phonon interactions characterized by and
, respectively, employing the dynamical mean-field theory combined with
Wilson's numerical renormalization group technique. A zero temperature phase
diagram of metal-insulator and insulator-insulator transitions at half-filling
is mapped out which exhibits the interplay between and . As () is
increased, a metal to Mott-Hubbard insulator (bipolaron insulator) transition
occurs, and the two insulating states are distinct and can not be adiabatically
connected. The nature of and transitions between the three states are
discussed.Comment: 5 pages, 4 figures. Submitted to Physical Review Letter
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