Limitations on squeezing and formation of the superposition of two macroscopically distinguishable states at fundamental frequency in the process of second harmonic generation

The results of numerical simulations of quantum state evolution in the process of second harmonic generation (SHG) are discussed. It is shown that at a particular moment of time in the fundamental mode initially coherent state turns into a superposition of two macroscopically distinguished states. The question of whether this superposition exhibits quantum interference is analyzed

Formation of Luminescence Centers in Oxygen-Deficient Cerium Oxide Nanocrystals

In this work the peculiarities of oxygen vacancies formation in cerium oxide nanoparticles for different external influences have been investigated by spectroscopic methods. The features of oxygen vacancies and therefore non-stoichiometric cerium oxide formation in CeO2 nanocrystals depending on the atmosphere of high temperature treatment were investigated. Stimulation of oxygen vacancies formation in reducing and neutral atmospheres was revealed. Occurrence of two different luminescence centers (viz. the charge-transfer complexes formed by Ce4+ and O2- ions, and Ce3+ ions stabilized by vacancies) after cerium oxide nanoparticles annealing in a neutral atmosphere has been observed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3544

Sub-Poissonian light and photocurrent shot-noise suppression in closed opto-electronic loop

We examine experimentally photocurrent noise reduction in the opto-electronic closed loop. Photocurrent noise density 12.5 dB below the shot-noise was observed. So large suppression was not reached in previous experiments and cannot be explained in terms of an ordinary sub-Poissonian light in the loop. We propose the concept of anticorrelation state for the description of light in the loop

Image language of the metarealism in the context of evolution of the mechanism of implementation of the metaphor in russophone poetry of the 20 century

In the late 1980s, a poetic school of metarealism begins with a special image language and type of trope, metabola. The basis of the "third trope" is the mechanism of implementation of the metaphor due to the evolution of the poetic language in the twentieth century. The author attempts here to show the place of the image language of metarealism in the development of Russian poetry. The implemented metaphor in the Silver Age changes from the instrument of expressing "mystical experiences" to the postsymbolic concept of "Logos", "The Word as such". In socialist realism, the implemented metaphor was either perceived as a formal outlier or was subordinate to the ideas of the "tamed avant-garde" of constructivism. And in exile, poets relied on the idea of inheriting post-symbolism or surrealism. The "Thaw" period is transitional for the history of metaphor. Two new types of metaphor: carnalization and metabola: deconstruction, the desolation of discourse, and reconstruction, the formation of a special metaphysical space ("metareality"). Thus, the metabola arises as an instrument of constructing complex poetic metaphysics taking in account discoveries in the field of of phylosophy and science (multiverse concept).В конце 1980-х гг. возникает поэтическая школа метареализма с особым образным языком и типом тропа, метаболой. В основе "третьего тропа" лежит механизм реализации метафоры, обусловленный эволюцией поэтического языка в ХХ веке. В статье предпринимается попытка показать место образного языка метареализма в развитии русской поэзии. Реализованная метафора в Серебряном веке изменяется от средства выражения "мистических переживаний" к постсимволистской концепции "Логоса", "Слова как такового". В соцреализме реализованная метафора или воспринималась как формальное излишество, или же подчинялась идеям "прирученного авангарда" конструктивизма. В эмиграции возникалиидеи наследования постсимволизму или же опора на сюрреализм. Период "Оттепели" является переходным и для истории метафоры. С установлением парадигмы русскоязычного постмодернизма, распадающегося на два течения - концептуализм и необарокко, возникают и два новых типа метафоры: карнализация и метабола: деконструкция, опустошение дискурса, и реконструкция, формирование особого метафизического пространства ("метареальности"). Таким образом, метабола возникает как средство построения сложной поэтической метафизики, учитывая открытия в области философии и науки (концепция мультиверса)

Function of metabola in metaphysics of Andrei Tavrov: the poem "Dirizhabl'"

Poetry of Andrei Tavrov is a continuation of the metaphysical project of metarealism.Поэзия Андрея Таврова является продолжением метафизического проекта метареализма

Measurement of qutrits

We proposed the procedure of measuring the unknown state of the three-level system - the qutrit, which was realized as the arbitrary polarization state of the single-mode biphoton field. This procedure is accomplished for the set of the pure states of qutrits; this set is defined by the properties of SU(2) transformations, that are done by the polarization transformers.Comment: 9 pages, 9 figure

On Exchange of Orbital Angular Momentum Between Twisted Photons and Atomic Electrons

We obtain an expression for the matrix element for a twisted (Laguerre-Gaussian profile) photon scattering from a hydrogen atom. We consider photons incoming with an orbital angular momentum (OAM) of $\ell \hbar$, carried by a factor of $e^{i \ell \phi}$ not present in a plane-wave or pure Gaussian profile beam. The nature of the transfer of $+2\ell$ units of OAM from the photon to the azimuthal atomic quantum number of the atom is investigated. We obtain simple formulae for these OAM flip transitions for elastic forward scattering of twisted photons when the photon wavelength $\lambda$ is large compared with the atomic target size $a$, and small compared the Rayleigh range $z_R$, which characterizes the collimation length of the twisted photon beam.Comment: 16 page

Feedback cooling of a single trapped ion

Based on a real-time measurement of the motion of a single ion in a Paul trap, we demonstrate its electro-mechanical cooling below the Doppler limit by homodyne feedback control (cold damping). The feedback cooling results are well described by a model based on a quantum mechanical Master Equation.Comment: 4 pages, 3 figure

Porosity of silica Stöber particles determined by spin-echo small angle neutron scattering.

Stöber silica particles are used in a diverse range of applications. Despite their widespread industrial and scientific uses, information on the internal structure of the particles is non-trivial to obtain and is not often reported. In this work we have used spin-echo small angle neutron scattering (SESANS) in conjunction with ultra small angle X-ray scattering (USAXS) and pycnometry to study an aqueous dispersion of Stöber particles. Our results are in agreement with models which propose that Stöber particles have a porous core, with a significant fraction of the pores inaccessible to solvent. For samples prepared from the same master sample in a range of H2O : D2O ratio solutions we were able to model the SESANS results for the solution series assuming monodisperse, smooth surfaced spheres of radius 83 nm with an internal open pore volume fraction of 32% and a closed pore fraction of 10%. Our results are consistent with USAXS measurements. The protocol developed and discussed here shows that the SESANS technique is a powerful way to investigate particles much larger than those studied using conventional small angle scattering methods