15,498 research outputs found
Optical properties of the charge-density-wave polychalcogenide compounds Te (=Nd, Sm and Gd)
We investigate the rare-earth polychalcogenide Te (=Nd, Sm and
Gd) charge-density-wave (CDW) compounds by optical methods. From the absorption
spectrum we extract the excitation energy of the CDW gap and estimate the
fraction of the Fermi surface which is gapped by the formation of the CDW
condensate. In analogy to previous findings on the related Te (n=2 and
3) families, we establish the progressive closing of the CDW gap and the
moderate enhancement of the metallic component upon chemically compressing the
lattice
The 2L1S/1L2S Degeneracy for Two Microlensing Planet Candidates Discovered by the KMTNet Survey in 2017
We report two microlensing planet candidates discovered by the Korea Microlensing Telescope Network (KMTNet) survey in 2017. However, both events have the 2L1S/1L2S degeneracy, which is an obstacle to claiming the discovery of the planets with certainty unless the degeneracy can be resolved. For KMT-2017-BLG-0962, the degeneracy cannot be resolved. If the 2L1S solution is correct, KMT-2017-BLG-0962 might be produced by a super Jupiter-mass planet orbiting a mid-M-dwarf host star. For KMT-2017-BLG-1119, the light-curve modeling favors the 2L1S solution but higher-resolution observations of the baseline object tend to support the 1L2S interpretation rather than the planetary interpretation. This degeneracy might be resolved by a future measurement of the lens-source relative proper motion. This study shows that the problem of resolving 2L1S/1L2S degeneracy exists over a much wider range of conditions than those considered by the theoretical study of Gaudi (1998)
The 2L1S/1L2S Degeneracy for Two Microlensing Planet Candidates Discovered by the KMTNet Survey in 2017
We report two microlensing planet candidates discovered by the Korea Microlensing Telescope Network (KMTNet) survey in 2017. However, both events have the 2L1S/1L2S degeneracy, which is an obstacle to claiming the discovery of the planets with certainty unless the degeneracy can be resolved. For KMT-2017-BLG-0962, the degeneracy cannot be resolved. If the 2L1S solution is correct, KMT-2017-BLG-0962 might be produced by a super Jupiter-mass planet orbiting a mid-M-dwarf host star. For KMT-2017-BLG-1119, the light-curve modeling favors the 2L1S solution but higher-resolution observations of the baseline object tend to support the 1L2S interpretation rather than the planetary interpretation. This degeneracy might be resolved by a future measurement of the lens-source relative proper motion. This study shows that the problem of resolving 2L1S/1L2S degeneracy exists over a much wider range of conditions than those considered by the theoretical study of Gaudi (1998)
Monolithic arrays of surface emitting laser NOR logic devices
Monolithic, cascadable, laser-logic-device arrays have been realized and characterized. The monolithic surface-emitting laser logic (SELL) device consists of an AlGaAs superlattice lasing around 780 nm connected to a heterojunction phototransistor (HPT) in parallel and a resistor in series. Arrays up to 8×8 have been fabricated, and 2×2 arrays show uniform characteristics. The optical logic output is switched off with 40 μW incident optical input
Monolithic arrays of surface emitting laser NOR logic devices
Monolithic, cascadable, laser-logic-device arrays have been realized and characterized. The monolithic surface-emitting laser logic (SELL) device consists of an AlGaAs superlattice lasing around 780 nm connected to a heterojunction phototransistor (HPT) in parallel and a resistor in series. Arrays up to 8×8 have been fabricated, and 2×2 arrays show uniform characteristics. The optical logic output is switched off with 40 μW incident optical input
Twitter and endorsed (fake) news: The influence of endorsement by strong ties, celebrities, and a user majority on credibility of fake news during the COVID-19 pandemic
Focusing on a widespread COVID-19 conspiracy theory, this study examines how social endorsement systems on Twitter, represented by retweets and metrics indicating the number of engagements by others, affect assessment of credibility of (fake) news. Expanding studies on social influence and endorsement-based heuristics, we hypothesized that Twitter users would consider fake news retweeted by a strong tie and with cues indicating a greater number of likes, comments, and retweets as more credible than news retweeted by a celebrity and without the cues. Through a two-by-two survey experiment among 267 Twitter users, we found evidence to support these hypotheses. We additionally found that the effectiveness of strong ties and celebrities as retweeters varied by users’ perceptions of their attributes and users’ interactions with them. These findings add to the literature of news credibility by demonstrating the effects of endorsements from social media contacts. Our study partly explains how and why fake news and disinformation spread in the networked online environment. We conclude this study by discussing implications for interventions of fake news on social medi
N3LO NN interaction adjusted to light nuclei in ab exitu approach
We use phase-equivalent transformations to adjust off-shell properties of
similarity renormalization group evolved chiral effective field theory NN
interaction (Idaho N3LO) to fit selected binding energies and spectra of light
nuclei in an ab exitu approach. We then test the transformed interaction on a
set of additional observables in light nuclei to verify that it provides
reasonable descriptions of these observables with an apparent reduced need for
three- and many-nucleon interactions.Comment: Revised text due to journal referee comments. 6 pages, 2 figure
Observation of Phase Separation in a Strongly-Interacting Imbalanced Fermi Gas
We have observed phase separation between the superfluid and the normal
component in a strongly interacting Fermi gas with imbalanced spin populations.
The in situ distribution of the density difference between two trapped spin
components is obtained using phase-contrast imaging and 3D image
reconstruction. A shell structure is clearly identified where the superfluid
region of equal densities is surrounded by a normal gas of unequal densities.
The phase transition induces a dramatic change in the density profiles as
excess fermions are expelled from the superfluid.Comment: 5 pages, 7 figure
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