792 research outputs found
Scanning a photonic crystal slab nanocavity by condensation of xenon
Allowing xenon or nitrogen gas to condense onto a photonic crystal slab nanocavity maintained at 10–20 K results in shifts of the nanocavity mode wavelength by as much as 5 nm (~=4 meV). This occurs in spite of the fact that the mode defect is achieved by omitting three holes to form the spacer. This technique should be useful in changing the detuning between a single quantum dot transition and the nanocavity mode for cavity quantum electrodynamics experiments, such as mapping out a strong coupling anticrossing curve. Compared with temperature scanning, it has a much larger scan range and avoids phonon broadening
Vacuum rabi splitting using a single quantum dot in a photonic crystal slab nanocavity
We report the observation of vacuum-field Rabi splitting (true strong coupling) between a single InAs quantum dot and a single photon in the mode of a photonic crystal slab nanocavity
Clinical outcomes of peri‐implantitis treatment and supportive care: A systematic review
To report the clinical outcomes for patients with implants treated for peri-implantitis who subsequently received supportive care (supportive peri-implant/periodontal therapy) for at least 3 years. A systematic search of multiple electronic databases, grey literature and hand searching, without language restriction, to identify studies including ≥10 patients was constructed. Data and risk of bias were explored qualitatively. Estimated cumulative survival at the implant- and patient-level was pooled with random-effects meta-analysis and explored for publication bias (funnel plot) at different time intervals. The search identified 5,761 studies. Of 83 records selected during screening, 65 were excluded through independent review (kappa = 0.94), with 18 retained for qualitative and 13 of those for quantitative assessments. On average, studies included 26 patients (median, IQR 21-32), with 36 implants (median, IQR 26-45). Study designs (case definitions of peri-implantitis, peri-implantitis treatment, supportive care) and population characteristics (patient, implant and prosthesis characteristics) varied markedly. Data extraction was affected by reduced reporting quality, but over 75% of studies had low risk of bias. Implant survival was 81.73%-100% at 3 years (seven studies), 74.09%-100% at 4 years (three studies), 76.03%-100% at 5 years (four studies) and 69.63%-98.72% at 7 years (two studies). Success and recurrence definitions were reported in five and two studies respectively, were heterogeneous, and those outcomes were unable to be explored quantitatively. Therapy of peri-implantitis followed by regular supportive care resulted in high patient- and implant-level survival in the medium to long term. Favourable results were reported, with clinical improvements and stable peri-implant bone levels in the majority of patients
Quantum Criticality in doped CePd_1-xRh_x Ferromagnet
CePd_1-xRh_x alloys exhibit a continuous evolution from ferromagnetism (T_C=
6.5 K) at x = 0 to a mixed valence (MV) state at x = 1. We have performed a
detailed investigation on the suppression of the ferromagnetic (F) phase in
this alloy using dc-(\chi_dc) and ac-susceptibility (\chi_ac), specific heat
(C_m), resistivity (\rho) and thermal expansion (\beta) techniques. Our results
show a continuous decrease of T_C (x) with negative curvature down to T_C = 3K
at x*= 0.65, where a positive curvature takes over. Beyond x*, a cusp in cac is
traced down to T_C* = 25 mK at x = 0.87, locating the critical concentration
between x = 0.87 and 0.90. The quantum criticality of this region is recognized
by the -log(T/T_0) dependence of C_m/T, which transforms into a T^-q (~0.5) one
at x = 0.87. At high temperature, this system shows the onset of valence
instability revealed by a deviation from Vegard's law (at x_V~0.75) and
increasing hybridization effects on high temperature \chi_dc and \rho.
Coincidentally, a Fermi liquid contribution to the specific heat arises from
the MV component, which becomes dominant at the CeRh limit. In contrast to
antiferromagnetic systems, no C_m/T flattening is observed for x > x_cr rather
the mentioned power law divergence, which coincides with a change of sign of
\beta. The coexistence of F and MV components and the sudden changes in the T
dependencies are discussed in the context of randomly distributed magnetic and
Kondo couplings.Comment: 11 pages, 11 figure
Improving Gravitational Wave Extraction Using Weyl Characteristic Fields
We present a detailed methodology for extracting the full set of Newman-Penrose Weyl scalars from numerically generated spacetimes without requiring a tetrad that is completely orthonormal or perfectly aligned to the principal null directions. We also describe an extrapolation technique for computing the Weyl scalars' contribution at asymptotic null infinity in post-processing. These methods have continued to be used to produce and waveforms for the Simulating eXtreme Spacetimes Waveform Catalog and now have been expanded to produce the entire set of Weyl scalars. These new waveform quantities are critical for the future of gravitational wave astronomy in order to understand the finite-amplitude gauge differences that can occur in numerical waveforms. We also present a new analysis of the accuracy of waveforms produced by the Spectral Einstein Code. While ultimately we expect Cauchy Characteristic Extraction to yield more accurate waveforms, the extraction techniques described here are far easier to implement and have already proven to be a viable way to produce production-level waveforms that can meet the demands of current gravitational-wave detectors
Beyond the Jaynes-Cummings model: circuit QED in the ultrastrong coupling regime
In cavity quantum electrodynamics (QED), light-matter interaction is probed
at its most fundamental level, where individual atoms are coupled to single
photons stored in three-dimensional cavities. This unique possibility to
experimentally explore the foundations of quantum physics has greatly evolved
with the advent of circuit QED, where on-chip superconducting qubits and
oscillators play the roles of two-level atoms and cavities, respectively. In
the strong coupling limit, atom and cavity can exchange a photon frequently
before coherence is lost. This important regime has been reached both in cavity
and circuit QED, but the design flexibility and engineering potential of the
latter allowed for increasing the ratio between the atom-cavity coupling rate
and the cavity transition frequency above the percent level. While these
experiments are well described by the renowned Jaynes-Cummings model, novel
physics is expected in the ultrastrong coupling limit. Here, we report on the
first experimental realization of a superconducting circuit QED system in the
ultrastrong coupling limit and present direct evidence for the breakdown of the
Jaynes-Cummings model.Comment: 5 pages, 3 figure
- …