13,246 research outputs found
Near-deterministic quantum teleportation and resource-efficient quantum computation using linear optics and hybrid qubits
We propose a scheme to realize deterministic quantum teleportation using
linear optics and hybrid qubits. It enables one to efficiently perform
teleportation and universal linear-optical gate operations in a simple and
near-deterministic manner using all-optical hybrid entanglement as off-line
resources. Our analysis shows that our new approach can outperforms major
previous ones when considering both the resource requirements and fault
tolerance limits.Comment: 10 pages, 5 figures; extended version, title, abstract and figures
changed, details added, to be published in Phys. Rev.
Preliminary evaluation of a reaction control system for the space station
The challenge, ground rules and criteria, some of the Reaction Control System (RCS) concepts, classical and modern design analysis, and simulation results which are applicable to the space station are presented
Long-Term Followup after Electrocautery Transurethral Resection of the Prostate for Benign Prostatic Hyperplasia
Introduction. For decades, transurethral resection of the prostate (TURP) has been the “gold standard” operation for benign prostatic hyperplasia (BPH) but is based mainly on historic data. The historic data lacks use of validated measures and current TURP differs significantly from that performed 30 years ago. Methods. Men who had undergone TURP between 2001 and 2005 were reviewed. International prostate symptom score (IPSS), quality of life (QOL) and peak urinary flow rate
(Qmax), and postvoid residual (PVR)
were recorded. Operative details and
postoperative
complications were documented. Patients were then invited to
attend for repeat assessment. Results. 91
patients participated. Mean follow-up time was 70 months. Mean
follow-up results were IPSS—7; QoL—1.5; Qmax—23 mL/s; PVR—45 mL. These were an improvement from baseline of
67%, 63%, 187%, and 80%, respectively. Early
complication rates were low, with no blood transfusions, TUR
syndrome, or deaths occurring. Urethral stricture rate was higher
than anticipated at 14%. Conclusion. This
study shows modern TURP still produces durable improvement in
voiding symptoms which remains comparable with historic studies.
This study, however, found a marked drop in early complications but,
conversely, a higher than expected incidence of urethral
strictures
Relation between the one-particle spectral function and dynamic spin susceptibility in superconducting BiSrCaCuO
Angle resolved photoemission spectroscopy (ARPES) provides a detailed view of
the renormalized band structure and, consequently, is a key to the self-energy
and the single-particle Green's function. Here we summarize the ARPES data
accumulated over the whole Brillouin zone for the optimally doped
BiSrCaCuO into a parametric model of the Green's
function, which we use for calculating the itinerant component of the dynamic
spin susceptibility in absolute units with many-body effects taken into
account. By comparison with inelastic neutron scattering (INS) data we show
that the itinerant component of the spin response can account for the integral
intensity of the experimental INS spectrum. Taking into account the bi-layer
splitting, we explain the magnetic resonances in the acoustic (odd) and optic
(even) INS channels.Comment: Submitted to PR
Detectability of dissipative motion in quantum vacuum via superradiance
We propose an experiment for generating and detecting vacuum-induced
dissipative motion. A high frequency mechanical resonator driven in resonance
is expected to dissipate energy in quantum vacuum via photon emission. The
photons are stored in a high quality electromagnetic cavity and detected
through their interaction with ultracold alkali-metal atoms prepared in an
inverted population of hyperfine states. Superradiant amplification of the
generated photons results in a detectable radio-frequency signal temporally
distinguishable from the expected background.Comment: 4 pages, 2 figure
Effects of pressure on the ferromagnetic state of the CDW compound SmNiC2
We report the pressure response of charge-density-wave (CDW) and
ferromagnetic (FM) phases of the rare-earth intermetallic SmNiC2 up to 5.5 GPa.
The CDW transition temperature (T_{CDW}), which is reflected as a sharp
inflection in the electrical resistivity, is almost independent of pressure up
to 2.18 GPa but is strongly enhanced at higher pressures, increasing from 155.7
K at 2.2 GPa to 279.3 K at 5.5 GPa. Commensurate with the sharp increase in
T_{CDW}, the first-order FM phase transition, which decreases with applied
pressure, bifurcates into the upper (T_{M1}) and lower (T_c) phase transitions
and the lower transition changes its nature to second order above 2.18 GPa.
Enhancement both in the residual resistivity and the Fermi-liquid T^2
coefficient A near 3.8 GPa suggests abundant magnetic quantum fluctuations that
arise from the possible presence of a FM quantum critical point.Comment: 5 pages, 5 figure
Reduced regional brain cortical thickness in patients with heart failure.
AimsAutonomic, cognitive, and neuropsychologic deficits appear in heart failure (HF) subjects, and these compromised functions depend on cerebral cortex integrity in addition to that of subcortical and brainstem sites. Impaired autoregulation, low cardiac output, sleep-disordered-breathing, hypertension, and diabetic conditions in HF offer considerable potential to affect cortical areas by loss of neurons and glia, which would be expressed as reduced cortical thicknesses. However, except for gross descriptions of cortical volume loss/injury, regional cortical thickness integrity in HF is unknown. Our goal was to assess regional cortical thicknesses across the brain in HF, compared to control subjects.Methods and resultsWe examined localized cortical thicknesses in 35 HF and 61 control subjects with high-resolution T1-weighted images (3.0-Tesla MRI) using FreeSurfer software, and assessed group differences with analysis-of-covariance (covariates; age, gender; p<0.05; FDR). Significantly-reduced cortical thicknesses appeared in HF over controls in multiple areas, including the frontal, parietal, temporal, and occipital lobes, more markedly on the left side, within areas that control autonomic, cognitive, affective, language, and visual functions.ConclusionHeart failure subjects show reduced regional cortical thicknesses in sites that control autonomic, cognitive, affective, language, and visual functions that are deficient in the condition. The findings suggest chronic tissue alterations, with regional changes reflecting loss of neurons and glia, and presumably are related to earlier-described axonal changes. The pathological mechanisms contributing to reduced cortical thicknesses likely include hypoxia/ischemia, accompanying impaired cerebral perfusion from reduced cardiac output and sleep-disordered-breathing and other comorbidities in HF
Microscopic Theory of Rashba Interaction in Magnetic Metal
Theory of Rashba spin-orbit coupling in magnetic metals is worked out from
microscopic Hamiltonian describing d-orbitals. When structural inversion
symmetry is broken, electron hopping between -orbitals generates chiral
ordering of orbital angular momentum, which combines with atomic spin-orbit
coupling to result in the Rashba interaction. Rashba parameter characterizing
the interaction is band-specific, even reversing its sign from band to band.
Large enhancement of the Rashba parameter found in recent experiments is
attributed to the orbital mixing of 3d magnetic atoms with non-magnetic heavy
elements as we demonstrate by first-principles and tight-binding calculations.Comment: 5 pages, 2 figure
Ground-state electric quadrupole moment of 31Al
Ground-state electric quadrupole moment of 31Al (I =5/2+, T_1/2 = 644(25) ms)
has been measured by means of the beta-NMR spectroscopy using a spin-polarized
31Al beam produced in the projectile fragmentation reaction. The obtained Q
moment, |Q_exp(31Al)| = 112(32)emb, are in agreement with conventional shell
model calculations within the sd valence space. Previous result on the magnetic
moment also supports the validity of the sd model in this isotope, and thus it
is concluded that 31Al is located outside of the island of inversion.Comment: 5 page
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