2,956 research outputs found
Optically-Triggered Nanoscale Memory Effect in a Hybrid Plasmonic-Phase Changing Nanostructure
Nanoscale devices, such as all-optical modulators and electro-optical transducers, can be implemented in heterostructures that integrate plasmonic nanostructures with functional active materials. Here we demonstrate all-optical control of a nanoscale memory effect in such a heterostructure by coupling the localized surface plasmon resonance (LSPR) of gold nanodisk arrays to a phase-changing material (PCM), vanadium dioxide (VO<inf>2</inf>). By latching the VO<inf>2</inf> in a distinct correlated metallic state during the insulator-to-metal transition (IMT), while concurrently exciting the hybrid nanostructure with one or more ultraviolet optical pulses, the entire phase space of this correlated state can be accessed optically to modulate the plasmon response. We find that the LSPR modulation depends strongly but linearly on the initial latched state, suggesting that the memory effect encoded in the plasmon resonance wavelength is linked to the strongly correlated electron states of the VO<inf>2</inf>. The continuous, linear variation of the electronic and optical properties of these model heterostructures opens the way to multiple design strategies for hybrid devices with novel optoelectronic functionalities, which can be controlled by an applied electric or optical field, strain, injected charge, or temperature.Department of Applied Physic
Multijet topology in high-energy nuclear collisions: jet broadening
This work presents the first theoretical investigation of the medium
modification of jet broadening as an event-shape observable in multijet final
states due to jet quenching in high-energy nuclear collisions. The partonic
spectrum of collisions with next-to-leading order (NLO) accuracy at
TeV is provided by the POWHEGPYTHIA8 event
generator, while the linear Boltzmann transport (LBT) model is utilized to
investigate the energy loss of fast partons as they traverse through the hot
and dense QCD medium. We present the jet broadening distributions in multijet
final states for both and PbPb collisions at TeV, then observe an enhancement at the small jet broadening region and
suppression at the large jet broadening region in PbPb collisions relative to
that in . This suggests that medium modification with parton energy loss in
the QGP leads to a more concentrated energy flow in all observed multijet
events in PbPb reactions. We also demonstrate that the intertwining of two
effects, the jet number reduction and the restructured contribution, results in
the novel behavior of nuclear modification of the jet broadening observable in
PbPb collisions.Comment: 9 pages, 6 figures, 2 table
Energy dependence of production in pp collisions with the PACIAE model
In this work we investigate the production in proton-proton
collisions at the center-of-mass energy () equal to 2.76, 5.02, 7, 8
and 13 TeV with a parton and hadron cascade model PACIAE 2.2a. It is based on
PYTHIA but extended considering the partonic and hadronic rescatterings before
and after hadronization, respectively. In the PYTHIA sector the
production quantum chromodynamics processes are selected specially and a bias
factor is proposed correspondingly. The calculated total cross sections, the
differential cross sections as a function of the transverse momentum and the
rapidity of in the forward rapidity region reproduce the corresponding
experimental measurements reasonably well. In the mid-rapidity region, the
double differential cross sections at 5.02, 7 and 13 TeV are also
in a good agreement with the experimental data. Moreover, we predict the double
differential cross section as well as the total cross section of at
8 TeV, which could be validated when the experimental data is
available.Comment: 6 pages, 8 figures, 3 table
Knee Osteoarthritis, Potential Mediators, and Risk of All-Cause Mortality: Data From the Osteoarthritis Initiative.
ObjectiveTo assess the relation of symptomatic knee osteoarthritis (OA), knee pain, and radiographic knee OA to All-cause mortality and to identify mediators in the causal pathway.MethodsParticipants from the Osteoarthritis Initiative were divided into 4 groups: 1) symptomatic knee OA (i.e., both radiographic knee OA [Kellgren/Lawrence grade ≥2] and knee pain); 2) knee pain only; 3) radiographic knee OA only; and 4) neither radiographic knee OA nor knee pain. We examined the relation of knee OA status to All-cause mortality using a multivariable Cox proportional hazards model and assessed the extent to which the association was mediated by disability, physical component summary (PCS) and mental component summary (MCS) scores for quality of life (QoL), and use of oral pain-relief medications (i.e., nonsteroidal antiinflammatory drugs and opioids).ResultsAmong 4,796 participants, 282 died over the 96-month follow-up period. Compared with those with neither radiographic knee OA nor knee pain, multivariable-adjusted hazard ratios (HRs) of mortality were 2.2 (95% confidence interval [95% CI] 1.6-3.1) for symptomatic knee OA, 0.9 (95% CI 0.6-1.4) for knee pain only, and 2.0 (95% CI 1.4-2.9) for radiographic knee OA only, respectively. Indirect effects (HRs) of symptomatic knee OA on mortality via disability and PCS of QoL were 1.1 (95% CI 1.0-1.4) and 1.2 (95% CI 1.0-1.4), respectively. No apparent mediation effect was observed through either MCS of QoL or oral pain-relief medications use.ConclusionParticipants with either symptomatic or radiographic knee OA were at an increased risk of All-cause mortality. Increased risk of mortality from symptomatic knee OA was partially mediated through its effect on disability and PCS of QoL
Local corrugation and persistent charge density wave in ZrTe3 with Ni intercalation
The mechanism of emergent bulk superconductivity in t ransition-metal intercalated ZrTe3 is investigated by studying the effect of Ni doping on the band structure and charge density wave (CDW). The study reports theoretical and experimental results in the range of Ni0.01ZrTe3 to Ni0.05ZrTe3. In the highest doped samples, bulk superconductivity with Tc < TCDW is observed, with a reduced TCDW compared with pure ZrTe3. Relativistic ab initio calculations reveal that Ni incorporation occurs preferentially through intercalation in the van der Waals gap. Analysis of the structural and electronic effects of intercalation indicate buckling of the Te sheets adjacent to the Ni site akin to a locally stabilized CDW-like lattice distortion. In contrast to the changes of TCDW observed in resistivity, experiments with low-temperature x-ray diffraction, angle-resolved-photoemission spectroscopy, as well as temperature-dependent resistivity reveal the nearly unchanged persistence of the CDW into the regime of bulk superconductivity. The CDW gap is found to be unchanged in its extent in momentum space, with the gap size also unchanged or possibly slightly reduced upon Ni intercalation. Both experimental observations suggest that superconductivity coexists with the CDW in NixZrTe3
The study on the structure of exotic states via beauty-hadron decays in collisions at
A dynamically constrained phase-space coalescence (DCPC) model was introduced
to study the exotic state yield for three possible
structures: tetraquark state, nuclear-like state, and molecular state
respectively, where the hadronic final states generated by the parton and
hadron cascade model (PACIAE). The / cross-section
ratio from beauty-hadron decays (non-prompt) based on the or
bound state in the decay chains as a
function of charged-particle multiplicity and transverse momentum in
collisions at are calculated. A tetraquark state
scenario from PACIAE+DCPC model shows better agreement with the LHCb and ATLAS
measurements for the non-prompt / cross-section
ratio distributions, indicating that the is more likely to
be a compact tetraquark state
Spectral Line-by-Line Pulse Shaping of an On-Chip Microresonator Frequency Comb
We report, for the first time to the best of our knowledge, spectral phase
characterization and line-by-line pulse shaping of an optical frequency comb
generated by nonlinear wave mixing in a microring resonator. Through
programmable pulse shaping the comb is compressed into a train of
near-transform-limited pulses of \approx 300 fs duration (intensity full width
half maximum) at 595 GHz repetition rate. An additional, simple example of
optical arbitrary waveform generation is presented. The ability to characterize
and then stably compress the frequency comb provides new data on the stability
of the spectral phase and suggests that random relative frequency shifts due to
uncorrelated variations of frequency dependent phase are at or below the 100
microHertz level.Comment: 18 pages, 4 figure
Energy dependence of light (anti)nuclei and (anti)hypertriton production in the Au-Au collision from to GeV
The energy dependence of light (anti)nuclei and (anti)hypertriton production
are investigated in central Au-Au collisions from AGS up to LHC energies at
midrapidity, using the parton and hadron cascade model (PACIAE) together with
the dynamically constrained phase-space coalescence model(DCPC). We find that
the yields, yield ratios of the antiparticles to their corresponding particles,
the coalescence parameters and the strangeness population factor of
light (anti)nuclei and (anti)hypertriton strongly depend on the energy.
Furthermore, we analyze and discuss the strangeness population factor and
the coalescence parameters , and find a transition point near by 20 GeV.
These results thus suggest the potential usefulness of the and of
light nuclei production in relativistic heavy-ion collisions as a direct probe
of the transition point associated with the QCD critical phenomena. The results
from PACIAE+DCPC model are well consistent with experimental data
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