1,265 research outputs found
A highly efficient two level diamond based single photon source
An unexplored diamond defect centre which is found to emit stable single
photons at a measured rate of 1.6 MHz at room temperature is reported. The
novel centre, identified in chemical vapour deposition grown diamond crystals,
exhibits a sharp zero phonon line at 734 nm with a full width at half maximum
of ~ 4 nm. The photon statistics confirm the center is a single emitter and
provides direct evidence of the first true two-level single quantum system in
diamond.Comment: 3 pages, 4 figure
Spin-orbit interaction in three-dimensionally bounded semiconductor nanostructures
The structural inversion asymmetry-induced spin-orbit interaction of
conduction band electrons in zinc-blende and wurtzite semiconductor structures
is analysed allowing for a three-dimensional (3D) character of the external
electric field and variation of the chemical composition. The interaction,
taking into account all remote bands perturbatively, is presented with two
contributions: a heterointerface term and a term caused by the external
electric field. They have generally comparable strength and can be written in a
unified manner only for 2D systems, where they can partially cancel each other.
For quantum wires and dots composed of wurtzite semiconductors new terms
appear, absent in zinc-blende structures, which acquire the standard Rashba
form in 2D systems.Comment: 18 pages, 1 figur
Experimental Demonstration of Squeezed State Quantum Averaging
We propose and experimentally demonstrate a universal quantum averaging
process implementing the harmonic mean of quadrature variances. The harmonic
mean protocol can be used to efficiently stabilize a set of fragile squeezed
light sources with statistically fluctuating noise levels. The averaged
variances are prepared probabilistically by means of linear optical
interference and measurement induced conditioning. We verify that the
implemented harmonic mean outperforms the standard arithmetic mean strategy.
The effect of quantum averaging is experimentally tested both for uncorrelated
and partially correlated noise sources with sub-Poissonian shot noise or
super-Poissonian shot noise characteristics.Comment: 4 pages, 5 figure
MPCVD processing of titanium-diffused LiNbO3 waveguides: optical characterisation and waveguide restoration
This paper presents some initial findings that explore the material properties of LiNbO3 which has been exposed to a microwave plasma-enhanced chemical vapor deposition (MPCVD) environment. The LiNbO3 was found to undergo a process known as 'reduction' when exposed to this environment. A technique was developed to reverse this process and recover the LiNbO3, which is a crucial first step towards the integration of diamond-based single photon sources with LiNbO3 waveguide technologies
International recommendations for outpatient palliative care and prehospital palliative emergencies - a prospective questionnaire-based investigation
BACKGROUND:
To determine the international recommendations and current practices for the treatment and prevention of palliative emergencies. The primary goal of the study was to gather information from experts on their nationally practised concepts.
METHODS:
One hundred and fifty self-report surveys were distributed by email to selected leading experts (palliative and emergency medical care) in Europe, North and South America, Africa, Asia, and Australia. An expert in this context was defined as an author of an article that was ranked by three reviewers as relevant to outpatient palliative and emergency medical .
RESULTS:
The total response rate was 61% (n = 92 experts). Survey responses were obtained from 35 different countries. The following standards in the treatment of palliative emergencies were recommended: (1) early integration of "Palliative Care Teams" (PCTs) and basic outpatient palliative care systems, (2) end-of-life discussions, (3) defined emergency medical documents, drug boxes, and "Do not attempt resuscitation" orders and (4) emergency medical training (physicians and paramedics).
CONCLUSIONS:
This study detected structurally and nationally differences in outpatient palliative care regarding the treatment of palliative emergencies. Accordingly, these differences should be discussed and adapted to the respective specifications of individual single countries. A single established outpatient palliative emergency medical care concept may be the basis for an overall out-of-hospital palliative care system
The interaction of 11Li with 208Pb
Background: 11Li is one of the most studied halo nuclei. The fusion of 11Li
with 208Pb has been the subject of a number of theoretical studies with widely
differing predictions, ranging over four orders of magnitude, for the fusion
excitation function.
Purpose: To measure the excitation function for the 11Li + 208Pb reaction.
Methods: A stacked foil/degrader assembly of 208Pb targets was irradiated
with a 11Li beam producing center of target beam energies from above barrier to
near barrier energies (40 to 29 MeV). The intensity of the 11Li beam (chopped)
was 1250 p/s and the beam on-target time was 34 hours. The alpha-decay of the
stopped evaporation residues was detected in a alpha-detector array at each
beam energy in the beam-off period (the beam was on for <= 5 ns and then off
for 170 ns).
Results: The 215At evaporation residues were associated with the fusion of
11Li with 208Pb. The 213,214At evaporation residues were formed by the breakup
of 11Li into 9Li + 2n, with the 9Li fusing with 208Pb. The 214At evaporation
residue appears to result from a "quasi-breakup" process.
Conclusions: Most of 11Li + 208Pb interactions lead to breakup with a small
fraction (<= 11%) leading to complete fusion.Comment: 25 pages, 11 figure
Two listeria outbreaks caused by smoked fish consumption-using whole-genome sequencing for outbreak investigations
The metal-poor dwarf irregular galaxy candidate next to Mrk 1172
In this work we characterise the properties of the object SDSS
J020536.84-081424.7, an extended nebular region with projected extension of kpc in the line of sight of the ETG Mrk 1172, using
unprecedented spectroscopic data from MUSE. We perform a spatially resolved
stellar population synthesis and estimate the stellar mass for both Mrk 1172
() and our object of study (). While the stellar content of Mrk 1172 is dominated by an old
( Gyr) stellar population, the extended nebular emission has its light
dominated by young to intermediate age populations (from Myr to
Gyr) and presents strong emission lines such as: H, [O III]
4959,5007, H, [N II]
6549,6585 and [S II] 6717,6732. Using
these emission lines we find that it is metal-poor (with 1/3
, comparable to the LMC) and is actively forming stars (
M yr), especially in a few bright clumpy knots that are
readily visible in H. The object has an ionised gas mass M. Moreover, the motion of the gas is well described
by a gas in circular orbit in the plane of a disk and is being affected by
interaction with Mrk 1172. We conclude that SDSS J020536.84-081424.7 is most
likely a dwarf irregular galaxy (dIGal)
Optical properties and optimization of electromagnetically induced transparency in strained InAs/GaAs quantum dot structures
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