922 research outputs found
Coherent switching of semiconductor resonator solitons
We demonstrate switching on and off of spatial solitons in a semiconductor
microresonator by injection of light coherent with the background illumination.
Evidence results that the formation of the solitons and their switching does
not involve thermal processes.Comment: 3 pages, 5 figure
Cybersecurity Development Problems in Ukraine
To date, the problem of cybersecurity is topical. Every day, each of us is faced
with the need to use information technology, beginning with the placement of
personal information on the Internet, to the use of ATMs, bank accounts, etc. Hence
the question arises whether this problem is controlled by national legislation and
whether our information is well protected
Spatial Resonator Solitons
Spatial solitons can exist in various kinds of nonlinear optical resonators
with and without amplification. In the past years different types of these
localized structures such as vortices, bright, dark solitons and phase solitons
have been experimentally shown to exist. Many links appear to exist to fields
different from optics, such as fluids, phase transitions or particle physics.
These spatial resonator solitons are bistable and due to their mobility suggest
schemes of information processing not possible with the fixed bistable elements
forming the basic ingredient of traditional electronic processing. The recent
demonstration of existence and manipulation of spatial solitons in emiconductor
microresonators represents a step in the direction of such optical parallel
processing applications. We review pattern formation and solitons in a general
context, show some proof of principle soliton experiments on slow systems, and
describe in more detail the experiments on semiconductor resonator solitons
which are aimed at applications.Comment: 15 pages, 32 figure
Spiritual and moral development of the personality in modern educational space
The culture and education are viewed as areas through which the process of the personality’s full development and formation takes place. This is the way how the human being, who is capable of the implementation and development of the experience accumulated by the mankind, is formed. The article proves the fact that education involves a person in a system of socially significant values; it forms the universal behavioural patterns and promotes the assimilation of human values. Taking into account the personality’s requests and social factors, it is extremely important for modern education to find optimal conditions for the harmonization of relations between the individual and the society, man and nature. This harmonization promotes the emergence and development of all physical and spiritual powers of the human being. Features mentioned above activate a new type of world perception and a system of values, which are impossible without understanding the ways of the modern man’s spiritual culture
New Signals of Quark-Gluon-Hadron Mixed Phase Formation
Here we present several remarkable irregularities at chemical freeze-out
which are found using an advanced version of the hadron resonance gas model.
The most prominent of them are the sharp peak of the trace anomaly existing at
chemical freeze-out at the center of mass energy 4.9 GeV and two sets of highly
correlated quasi-plateaus in the collision energy dependence of the entropy per
baryon, total pion number per baryon, and thermal pion number per baryon which
we found at the center of mass energies 3.8-4.9 GeV and 7.6-10 GeV. The low
energy set of quasi-plateaus was predicted a long time ago. On the basis of the
generalized shock-adiabat model we demonstrate that the low energy correlated
quasi-plateaus give evidence for the anomalous thermodynamic properties inside
the quark-gluon-hadron mixed phase. It is also shown that the trace anomaly
sharp peak at chemical freeze-out corresponds to the trace anomaly peak at the
boundary between the mixed phase and quark gluon plasma. We argue that the high
energy correlated quasi-plateaus may correspond to a second phase transition
and discuss its possible origin and location. Besides we suggest two new
observables which may serve as clear signals of these phase transformations.Comment: 14 pages, 4 figures, new signals of QGP formation are suggeste
Dark polariton-solitons in semiconductor microcavities
We report the existence, symmetry breaking and other instabilities of dark
polariton-solitons in semiconductor microcavities operating in the strong
coupling regime. These half-light half-matter solitons are potential candidates
for applications in all-optical signal processing. Their excitation time and
required pump powers are a few orders of magnitude less than those of their
weakly coupled light-only counterparts.Comment: submitted to PR
Hadron Resonance Gas Model with Induced Surface Tension
Here we present a physically transparent generalization of the multicomponent
Van der Waals equation of state in the grand canonical ensemble. For the
one-component case the third and fourth virial coefficients are calculated
analytically. It is shown that an adjustment of a single model parameter allows
us to reproduce the third and fourth virial coefficients of the gas of hard
spheres with small deviations from their exact values. A thorough comparison of
the compressibility factor and speed of sound of the developed model with the
one and two component Carnahan-Starling equation of state is made. It is shown
that the model with the induced surface tension is able to reproduce the
results of the Carnahan-Starling equation of state up to the packing fractions
0.2-0.22 at which the usual Van der Waals equation of state is inapplicable. At
higher packing fractions the developed equation of state is softer than the gas
of hard spheres and, hence, it breaks causality in the domain where the
hadronic description is expected to be inapplicable. Using this equation of
state we develop an entirely new hadron resonance gas model and apply it to a
description of the hadron yield ratios measured at AGS, SPS, RHIC and ALICE
energies of nuclear collisions. The achieved quality of the fit per degree of
freedom is about 1.08. We confirm that the strangeness enhancement factor has a
peak at low AGS energies, while at and above the highest SPS energy of
collisions the chemical equilibrium of strangeness is observed. We argue that
the chemical equilibrium of strangeness, i.e. , observed
above the center of mass collision energy 4.3 GeV may be related to the
hadronization of quark gluon bags which have the Hagedorn mass spectrum, and,
hence, it may be a new signal for the onset of deconfinement
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