214 research outputs found
Selective entanglement breaking
We discuss the cases where local decoherence selectively degrades one type of
entanglement more than other types. A typical case is called state ordering
change, in which two input states with different amounts of entanglement
undergoes a local decoherence and the state with the larger entanglement
results in an output state with less entanglement than the other output state.
We are also interested in a special case where the state with the larger
entanglement evolves to a separable state while the other output state is still
entangled, which we call selective entanglement breaking. For three-level or
larger systems, it is easy to find examples of the state ordering change and
the selective entanglement breaking, but for two-level systems it is not
trivial whether such situations exist. We present a new strategy to construct
examples of two-qubit states exhibiting the selective entanglement breaking
regardless of entanglement measure. We also give a more striking example of the
selective entanglement breaking in which the less entangled input state has
only an infinitesimal amount of entanglement.Comment: 6 pages, 2 figure
60 Gbps real-time wireless communications at 300 GHz carrier using a Kerr microcomb
Future wireless communication infrastructure will rely on terahertz systems
that can support an increasing demand for large-bandwidth, ultra-fast wireless
data transfer. In order to satisfy this demand, compact, low-power, and low
noise sources of terahertz radiation are being developed. A promising route to
achieving this goal is combining photonic-integrated optical frequency combs
with fast photodiodes for difference frequency generation in the THz. Here, we
demonstrate wireless communications using a 300 GHz carrier wave generated via
photomixing of two optical tones originating from diode lasers that are
injection locked to a dissipative Kerr soliton frequency microcomb. We achieve
transfer rates of 80 Gbps using homodyne detection and 60 Gbps transmitting
simultaneously both data and clock signals in a dual-path wireless link. This
experimental demonstration paves a path towards low-noise and integrated
photonic millimeter-wave transceivers for future wireless communication
systems
Universality and superiority in preference for chromatic composition of art paintings
Color composition in paintings is a critical factor affecting observers' aesthetic judgments. We examined observers' preferences for the color composition of Japanese and Occidental paintings when their color gamut was rotated. In the experiment, observers were asked to select their preferred image from original and three hue-rotated images in a four-alternative forced choice paradigm. Despite observers' being unfamiliar with the presented artwork, the original paintings (0 degrees) were preferred more frequently than the hue-rotated ones. Furthermore, the original paintings' superiority was observed when the images were divided into small square pieces and their positions randomized (Scrambled condition), and when the images were composed of square pieces collected from different art paintings and composed as patchwork images (Patchwork condition). Therefore, the original paintings' superiority regarding preference was quite robust, and the specific objects in the paintings associated with a particular color played only a limited role. Rather, the original paintings' general trend in color statistics influenced hue-angle preference. Art paintings likely share common statistical regulations in color distributions, which may be the basis for the universality and superiority of the preference for original paintings.- We thank Dr. Yukinori Misaki at Kagawa National Institute of Technology, Japan and Ms. Nobuyo Okada and Ms. Kanako Maruchi at Toyohashi City Museum of Art and History, Japan for assisting in the measurement of art paintings. This work was supported by JSPS KAKENHI Grant Number JP19H01119 and 20H05956, and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020
Evolution of Star Formation in the UKIDSS Ultra Deep Survey Field - II. Star Formation as a Function of Stellar Mass Between z=1.46 and z=0.63
We present new results on the evolution of the cosmic star formation rate as a function of stellar mass in the SXDS-UDS field. We make use of narrow-band selected emission line galaxies in four redshift slices between z = 1.46 and z = 0.63, and compute stellar masses by fitting a series of templates to recreate each galaxy's star formation history. We determine mass-binned luminosity functions in each redshift slice, and derive the star formation rate density (rhoSFR) as a function of mass using the [OIII] or [OII] emission lines. We calculate dust extinction and metallicity as a function of stellar mass, and investigate the effect of these corrections on the shape of the overall rhoSFR(M). We find that both these corrections are crucial for determining the shape of the rhoSFR(M), and its evolution with redshift. The fully corrected rhoSFR(M) is a relatively flat distribution, with the normalisation moving towards lower values of rhoSFR with increasing cosmic time/decreasing redshift, and requiring star formation to be truncated across all masses studied here. The peak of rhoSFR(M) is found in the 10^10.5<Msun<10^11.0 mass bin at z = 1.46. In the lower redshift slices the location of the peak is less certain, however low mass galaxies in the range 10^7.0<Msun<10^8.0 play an important part in the overall rhoSFR(M) out to at least z ~ 1.2
All-optical trion generation in single walled carbon nanotubes
We present evidence of all optical trion generation and emission in undoped
single walled carbon nanotubes (SWCNTs). Luminescence spectra, recorded on
individual SWCNTs over a large CW excitation intensity range, show trion
emission peaks red-shifted with respect to the bright exciton peak. Clear
chirality dependence is observed for 22 separate SWCNT species, allowing for
determination of electron-hole exchange interaction and trion binding energy
contributions. Luminescence data together with ultrafast pump probe experiments
on chirality sorted bulk samples suggest that exciton-exciton annihilation
processes generate dissociated carriers that allow for trion creation upon a
subsequent photon absorption event.Comment: 13 pages, 4 figure
Laporan Pengabdian kepada Masyarakat : Pendampingan Teknis dalam bentuk FGD (Forum Group Discusion) Pemberdayaan Masyarakat dalam memperbaiki Infrastruktur Drainase sebagai Pencegahan Genangan Air dalampengembangan Bahan dan Infrastruktur Jalan Desa Tuapejat Kabupaten Mentawai
Seperti kita ketahui bersama drainase adalah suatu terminologi yang digunakan untuk
menyatakan sistem-sistem yang berkaitan dengan masalah kelebihan air, baik diatas
maupun dibawah permukaan tanah.
Tidak terbatas pada teknik pembuangan air yang berlebih, ttp juga keterkaitan dengan
aspek kehidupan dalam kawasan perkotaan. Drainase yang cukup merupakan faktor
penting dalam lokasi dan geometrik desain jalan raya. Fasilitas drainase di setiap jalan raya
atau jalan harus memadai dan disediakan untuk aliran air dari permukaan trotoar ke saluran
drainase.
Drainase yang tidak memadai pada akhirnya akan mengakibatkan kerusakan serius pada
struktur jalan raya. Selain itu, lalu lintas dapat diperlambat oleh akumulasi air pada
pavement jalan, dan kecelakaan dapat terjadi sebagai akibat dari tergelincirnya roda
kendaraan.
Di sinilah pentingnya manajemen air untuk pembangunan jalan raya dialokasikan untuk
fasilitas drainase. Sebagai gambaran untuk konstruksi pengendalian erosi dan struktur
drainase, seperti gorong-gorong, jembatan, saluran, dan parit.
Permasalahan yang dihadapi dalam pembangunan jalan raya terutama berkaitan dengan
dua sumber air
Initial Results from the Nobeyama Molecular Gas Observations of Distant Bright Galaxies
We present initial results from the CO survey toward high redshift galaxies
using the Nobeyama 45m telescope. Using the new wide bandwidth spectrometer
equipped with a two-beam SIS receiver, we have robust new detections of three
high redshift (z=1.6-3.4) submillimeter galaxies (SXDF 1100.001, SDP9, and
SDP17), one tentative detection (SDSS J160705+533558), and one non-detection
(COSMOS-AzTEC1). The galaxies observed during the commissioning phase are
sources with known spectroscopic redshifts from previous optical or from
wide-band submm spectroscopy. The derived molecular gas mass and line widths
from Gaussian fits are ~10^11 Msun and 430-530 km/s, which are consistent with
previous CO observations of distant submm galaxies and quasars. The
spectrometer that allows a maximum of 32 GHz instantaneous bandwidth will
provide new science capabilities at the Nobeyama 45m telescope, allowing us to
determine redshifts of bright submm selected galaxies without any prior
redshift information.Comment: 4 pages, 1 figure, PASJ Letter Accepte
Interplay of the Inverse Proximity Effect and Magnetic Field in Out-of-Equilibrium Single-Electron Devices
We show that a weak external magnetic field affects significantly nonequilibrium quasiparticle (QP) distributions under the conditions of the inverse proximity effect, using the single-electron hybrid turnstile as a generic example. Inverse proximity suppresses the superconducting gap in superconducting leads in the vicinity of turnstile junctions, thus, trapping hot QPs in this region. An external magnetic field creates additional QP traps in the leads in the form of vortices or regions with a reduced superconducting gap resulting in the release of QPs away from the junctions. We present clear experimental evidence of the interplay of the inverse proximity effect and magnetic field revealing itself in the superconducting gap enhancement and significant improvement of the turnstile characteristics. The observed interplay and its theoretical explanation in the context of QP overheating are important for various superconducting and hybrid nanoelectronic devices, which find applications in quantum computation, photon detection, and quantum metrology
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