2,412 research outputs found
Increasing future gravitational-wave detectors sensitivity by means of amplitude filter cavities and quantum entanglement
The future laser interferometric gravitational-wave detectors sensitivity can
be improved using squeezed light. In particular, recently a scheme which uses
the optical field with frequency dependent squeeze factor, prepared by means of
a relatively short (~30 m) amplitude filter cavity, was proposed
\cite{Corbitt2004-3}. Here we consider an improved version of this scheme,
which allows to further reduce the quantum noise by exploiting the quantum
entanglement between the optical fields at the filter cavity two ports.Comment: 10 pages, 7 figure
Quantum variational measurement in the next generation gravitational-wave detectors
A relatively simple method of overcoming the Standard Quantum Limit in the
next-generation Advanced LIGO gravitational wave detector is considered. It is
based on the quantum variational measurement with a single short (a few tens of
meters) filter cavity. Estimates show that this method allows to reduce the
radiation pressure noise at low frequencies () to the level
comparable with or smaller than the low-frequency noises of non-quantum origin
(mirrors suspension noise, mirrors internal thermal noise, and gravity
gradients fluctuations).Comment: 12 pages, 4 figures; NSNS SNR estimates added; misprints correcte
Vitrification of human immature oocytes before and after in vitro maturation: a review
The use of immature oocytes subjected to in vitro maturation (IVM) opens interesting perspectives for fertility preservation where ovarian reserves are damaged by pathologies or therapies, as in PCO/PCOS and cancer patients. Human oocyte cryopreservation may offer some advantages compared to embryo freezing, such as fertility preservation in women at risk of losing fertility due to oncological treatment or chronic disease, egg donation and postponing childbirth. It also eliminates religious and/or other ethical, legal, and moral concerns of embryo freezing. In addition, a successful oocyte cryopreservation program could eliminate the need for donor and recipient menstrual cycle synchronization. Recent advances in vitrification technology have markedly improved the oocyte survival rate after warming, with fertilization and implantation rates comparable with those of fresh oocytes. Healthy live births can be achieved from the combination of IVM and vitrification, even if vitrification of in vivo matured oocytes is still more effective. Recently, attention is given to highlight whether vitrification procedures are more successful when performed before or after IVM, on immature GV-stage oocytes, or on in vitro matured MII-stage oocytes. In this review, we emphasize that, even if there are no differences in survival rates between oocytes vitrified prior to or post-IVM, reduced maturation rates of immature oocytes vitrified prior to IVM can be, at least in part, explained by underlying ultrastructural and biomolecular alterations
Optimal configurations of filter cavity in future gravitational-wave detectors
Sensitivity of future laser interferometric gravitational-wave detectors can
be improved using squeezed light with frequency-dependent squeeze angle and/or
amplitude, which can be created using additional so-called filter cavities.
Here we compare performances of several variants of this scheme, proposed
during last years, assuming the case of a single relatively short (tens of
meters) filter cavity suitable for implementation already during the life cycle
of the second generation detectors, like Advanced LIGO. Using numerical
optimization, we show that the phase filtering scheme proposed by Kimble et al
[Phys.Rev.D 65, 022002 (2001)] looks as the best candidate for this scenario.Comment: 17 pages, 5 figure
Overcoming detection loss and noise in squeezing-based optical sensing
Among the known resources of quantum metrology, one of the most practical and efficient is squeezing. Squeezed states of atoms and light improve the sensing of the phase, magnetic field, polarization, mechanical displacement. They promise to considerably increase signal-to-noise ratio in imaging and spectroscopy, and are already used in real-life gravitational-wave detectors. But despite being more robust than other states, they are still very fragile, which narrows the scope of their application. In particular, squeezed states are useless in measurements where the detection is inefficient or the noise is high. Here, we experimentally demonstrate a remedy against loss and noise: strong noiseless amplification before detection. This way, we achieve loss-tolerant operation of an interferometer fed with squeezed and coherent light. With only 50% detection efficiency and with noise exceeding the level of squeezed light more than 50 times, we overcome the shot-noise limit by 6 dB. Sub-shot-noise phase sensitivity survives up to 87% loss. Application of this technique to other types of optical sensing and imaging promises a full use of quantum resources in these fields
Energy Dependence of Breakup Cross Sections of Halo Nucleus 8B and Effective Interactions
We study the energy dependence of the cross sections for nucleon removal of
8B projectiles. It is shown that the Glauber model calculations with
nucleon-nucleon t-matrix reproduce well the energy dependence of the breakup
cross sections of 8B. A DWBA model for the breakup cross section is also
proposed and results are compared with those of the Glauber model. We show that
to obtain an agreement between the DWBA calculations, the Glauber formalism,
and the experimental data, it is necessary to modify the energy behavior of the
effective interaction. In particular, the breakup potential has a quite
different energy dependence than the strong absorption potential.Comment: 13 pages, 4 figure
Single-photon optomechanics in the strong coupling regime
We give a theoretical description of a coherently driven opto-mechanical
system with a single added photon. The photon source is modeled as a cavity
which initially contains one photon and which is irreversibly coupled to the
opto-mechanical system. We show that the probability for the additional photon
to be emitted by the opto-mechanical cavity will exhibit oscillations under a
Lorentzian envelope, when the driven interaction with the mechanical resonator
is strong enough. Our scheme provides a feasible route towards quantum state
transfer between optical photons and micromechanical resonators.Comment: 14 pages, 6 figure
The effect of Maneb on implantation, fecundity rate and the thyroid activity in the rabbit
The fungicide Maneb is a member of the family of dithiocarbamates that is used in the control of the fungal diseases of plants. The purpose of this work is to examine the effect of Maneb on implantation and thyroid activity at doses of 5, 10 and 50 mg/kg/day by gavage for 10 days in the domestic female rabbit, Oryctolagus cuniculus. The rabbits were sacrificed on the 11th day of pregnancy. The results indicate an increase in the body weight in the treated female. An increase is also observed in the weightof liver in the treated females with a darker color. There is 50% of inhibition of implantation in the group treated with the higher dose (50 mg/kg/day) when compared with control rabbit. The inhibition of implantation by Maneb may be to due to hormonal imbalance
- …