13,891 research outputs found
Mode-Locked Two-Photon States
The concept of mode locking in laser is applied to a two-photon state with
frequency entanglement. Cavity enhanced parametric down-conversion is found to
produce exactly such a state. The mode-locked two-photon state exhibits a
comb-like correlation function. An unbalanced Hong-Ou-Mandel type
interferometer is used to measure the correlation function. A revival of the
typical interference dip is observed. We will discuss schemes for engineering
of quantum states in time domain.Comment: 4 pages, 5 figure
The effects of adrenalectomy and corticsteroid injection on the fibrinolytic activity of complex heparin compounds in the blood during immobilization
Total non-enzymatic fibrinolytic activity in the blood of rats increased three times in response to stress caused by 30 minute immobilization, and the activity of epinephrine-heparin complex increased nine times. In adrenalectomized animals, which showed a weak response to the same stress, intraperitoneal injection of hydrocortisone 30 minutes prior to immobilization normalized the response. Obtained results indicate that adrenalectomy leads to sharp reduction of heparin complexing with thromogenic proteins and epinephrine, while substitution therapy with hydrocortisone restores anticoagulation system function
Spontaneously Localized Photonic Modes Due to Disorder in the Dielectric Constant
We present the first experimental evidence for the existence of strongly
localized photonic modes due to random two dimensional fluctuations in the
dielectric constant. In one direction, the modes are trapped by ordered Bragg
reflecting mirrors of a planar, one wavelength long, microcavity. In the cavity
plane, they are localized by disorder, which is due to randomness in the
position, composition and sizes of quantum dots located in the anti-node of the
cavity. We extend the theory of disorder induced strong localization of
electron states to optical modes and obtain quantitative agreement with the
main experimental observations.Comment: 6 page
A mechanical Turing machine: blueprint for a biomolecular computer
We describe a working mechanical device that embodies the theoretical computing machine of Alan Turing, and as such is a universal programmable computer. The device operates on three-dimensional building blocks by applying mechanical analogues of polymer elongation, cleavage and ligation, movement along a polymer, and control by molecular recognition unleashing allosteric conformational changes. Logically, the device is not more complicated than biomolecular machines of the living cell, and all its operations are part of the standard repertoire of these machines; hence, a biomolecular embodiment of the device is not infeasible. If implemented, such a biomolecular device may operate in vivo, interacting with its biochemical environment in a program-controlled manner. In particular, it may ‘compute’ synthetic biopolymers and release them into its environment in response to input from the environment, a capability that may have broad pharmaceutical and biological applications
A generalized nonlinear Schr\"odinger equation as model for turbulence, collapse, and inverse cascade
A two-dimensional generalized cubic nonlinear Schr\"odinger equation with
complex coefficients for the group dispersion and nonlinear terms is used to
investigate the evolution of a finite-amplitude localized initial perturbation.
It is found that modulation of the latter can lead to side-band formation, wave
condensation, collapse, turbulence, and inverse cascade, although not all
together nor in that order.Comment: 12 pages, 5 figure
Draft genome sequences of gammaproteobacterial methanotrophs isolated from lake washington sediment.
The genomes of Methylosarcina lacus LW14(T) (=ATCC BAA-1047(T) = JCM 13284(T)), Methylobacter sp. strain 21/22, Methylobacter sp. strain 31/32, Methylomonas sp. strain LW13, Methylomonas sp. strain MK1, and Methylomonas sp. strain 11b were sequenced and are reported here. All the strains are obligately methanotrophic bacteria isolated from the sediment of Lake Washington
On different actions for the vacuum of bosonic string field theory
We study a family of kinetic operators in string field theory describing the
theory around the closed string vacuum. Those operators are based on the
analytical classical solutions of Takahashi and Tanimoto and are analogous to
the pure ghost action usually referred to as "vacuum string field theory," but
are much more general, and less singular than the pure ghost operator. The
closed string vacuum is related to the D-brane vacuum by large, singular, gauge
transformations or field redefinition, and all those different representations
are related to each other by small gauge transformations. We try to clarify the
nature of this singular gauge transformation. We also show that by choosing the
Siegel gauge one recovers the propagator proposed in hep-th/0207266 that
generates closed string surfaces.Comment: 15 page
Reducing the weak lensing noise for the gravitational wave Hubble diagram using the non-Gaussianity of the magnification distribution
Gravitational wave sources are a promising cosmological standard candle
because their intrinsic luminosities are determined by fundamental physics (and
are insensitive to dust extinction). They are, however, affected by weak
lensing magnification due to the gravitational lensing from structures along
the line of sight. This lensing is a source of uncertainty in the distance
determination, even in the limit of perfect standard candle measurements. It is
commonly believed that the uncertainty in the distance to an ensemble of
gravitational wave sources is limited by the standard deviation of the lensing
magnification distribution divided by the square root of the number of sources.
Here we show that by exploiting the non-Gaussian nature of the lensing
magnification distribution, we can improve this distance determination,
typically by a factor of 2--3; we provide a fitting formula for the effective
distance accuracy as a function of redshift for sources where the lensing noise
dominates.Comment: matches PRD accepted version (expanded description of the
cosmological parameter space + minor changes
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