Origin of Pure Spin Superradiance

The question addressed in this paper is: What originates pure spin superradiance in a polarized spin system placed inside a resonator? The term "pure" means that no initial coherence is imposed on spins, and its appearance manifests a purely self-organized collective effect. The consideration is based on a microscopic model with dipole spin interactions. An accurate solution of evolution equations is given. The results show that the resonator Nyquist noise does not play, contrary to the common belief, any role in starting spin superradiance, but the emergence of the latter is initiated by local spin fluctuations. The decisive role of nonsecular dipole interactions is stressed.Comment: 1 file, 13 pages, RevTe

Magnetic and electrical properties of the half-metallic ferromagnets Co2CrAl

This paper presents the results of measurements of the magnetic and electrical properties of the ferromagnetic alloy Co2CrAl in two structural states: (i) after severe plastic deformation and (ii) after shortterm high-temperature annealing of the deformed specimens. The experiments have been performed at temperatures in the range from 2 to 900 K in magnetic fields H ≤ 50 kOe. The ferromagnetic Curie temperature TC and the paramagnetic Curie temperature Θ have been determined (TC = 305 K and Θ = 326 K), as well as the spontaneous magnetic moment μS and the effective magnetic moment μeff per molecule of the alloy (μS = 1.62 μB and μeff 2 = 8.2 μB 2). It has been shown that the magnetic crystalline anisotropy energy of the alloy is on the order of ∼5 × 105 erg/g. The specific features of the electrical properties are associated with the presence of an energy gap in the electronic spectrum near the Fermi level EF and with the change in the parameters of the energy gap as a function of the temperature. © 2013 Pleiades Publishing, Ltd

Semantic features of the phraseological units with the component light within the artistic discourse

Conduct lexical and semantic analysis on the concept light in the artistic discourse of postmodern fictio

Nonlinear Spin Dynamics in Ferromagnets with Electron-Nuclear Coupling

Nonlinear spin motion in ferromagnets is considered with nonlinearity due to three factors: (i) the sample is prepared in a strongly nonequilibrium state, so that evolution equations cannot be linearized as would be admissible for spin motion not too far from equilibrium, (ii) the system considered consists of interacting electron and nuclear spins coupled with each other via hyperfine forces, and (iii) the sample is inserted into a coil of a resonant electric circuit producing a resonator feedback field. Due to these nonlinearities, coherent motion of spins can develop, resulting in their ultrafast relaxation. A complete analysis of mechanisms triggering such a coherent motion is presented. This type of ultrafast coherent relaxation can be used for studying intrinsic properties of magnetic materials.Comment: 1 file, LaTex, 23 page

Охрана окружающей среды в Германии и России

Im Artikel wird der ökologische Zustand der Umwelt Deutschlands und Russlands verglichen. Es wird bemerkt, dass die Probleme in beiden Ländern existieren, die mit der Ökologie verbunden sind. Das Ziel des Artikels ist, die Umwelt zwei Länder zu vergleichen und festzustellen, auf welche Weise man das vorliegende Problem löst. Die vergleichende Analyse des Zustandes der Umwelt und der Bekämpfung mit den existierenden Problemen hilft nicht nur, die Nachteile in der ökologischen Politik aufzufinden, sondern auch die Richtungen ihrer Korrektur zu bestimmen. Mit Hilfe der Nutzung der Internet-Quellen sind die Methoden der Verbesserung der Umwelt Deutschlands und Russlands festgestellt. Im Vergleich zu Russland nimmt Deutschland den führenden Platz in der Bekämpfung mit ökologischen Problemen. In diesem Zusammenhang braucht Russland mehr Aufmerksamkeit der Ökologie zuzuteilen. Das Problem, darum es sich handelt, fordert die sorgfältigeren Forschungen. Die Menschheit denkt manchmal nicht daran, welchen Schaden sie der Umwelt von den Handlungen zufügt. Die heranrückende Ökokatastrophe kann man vermeiden, wenn wir heute das endlich bewusst sind. Der Artikel ist für die Studenten der Geistesspezialisierung, sowie für alle Leser empfohlen, die sich für die Fragen der Ökologie interessieren.В статье сравнивается экологическое состояние окружающей среды Германии и России. Отмечается, что в обеих странах существуют проблемы, связанные с экологией. Целью статьи является сравнить окружающую среду двух стран и выявить, каким образом решается данная проблема. Сравнительный анализ состояния окружающей среды и борьбы с существующими проблемами помогает не только обнаружить недостатки в экологической политике, но и определить направления их исправления. При помощи использования интернет-источников выявлены методы улучшения окружающей среды Германии и России. По сравнению с Россией Германия занимает лидирующее место по борьбе с экологическими проблемами. В связи с этим России требуется уделять большее внимание своей экологии. Проблема, о которой идёт речь, требует более тщательных исследований. Человечество иногда не задумывается о том, какой урон наносит окружающей среде своими действиями. Надвигающейся экологической катастрофы можно избежать, если мы сегодня, наконец, осознаем это. Статья рекомендована для студентов гуманитарной специализации, а также для всех читателей, интересующихся вопросами экологии

CYCLOADDITION OF 1,4-CNCO DIPOLES GENERATED FROM DIPYRAZOLODIOXADIAZOCINES

This work was supported by the Russian Science Foundation, project # 19-13-00290

Coherent spin relaxation in molecular magnets

Numerical modelling of coherent spin relaxation in nanomagnets, formed by magnetic molecules of high spins, is accomplished. Such a coherent spin dynamics can be realized in the presence of a resonant electric circuit coupled to the magnet. Computer simulations for a system of a large number of interacting spins is an efficient tool for studying the microscopic properties of such systems. Coherent spin relaxation is an ultrafast process, with the relaxation time that can be an order shorter than the transverse spin dephasing time. The influence of different system parameters on the relaxation process is analysed. The role of the sample geometry on the spin relaxation is investigated.Comment: Latex file, 22 pages, 7 figure

Nonadiabatic Dynamics of Atoms in Nonuniform Magnetic Fields

Dynamics of neutral atoms in nonuniform magnetic fields, typical of quadrupole magnetic traps, is considered by applying an accurate method for solving nonlinear systems of differential equations. This method is more general than the adiabatic approximation and, thus, permits to check the limits of the latter and also to analyze nonadiabatic regimes of motion. An unusual nonadiabatic regime is found when atoms are confined from one side of the z-axis but are not confined from another side. The lifetime of atoms in a trap in this semi-confining regime can be sufficiently long for accomplishing experiments with a cloud of such atoms. At low temperature, the cloud is ellipsoidal being stretched in the axial direction and moving along the z-axis. The possibility of employing the semi-confining regime for studying the relative motion of one component through another, in a binary mixture of gases is discussed.Comment: 1 file, 17 pages, RevTex, 2 table

Processing Information by Punctuated Spin Superradiance

The possibility of realizing the regime of punctuated spin superradiance is advanced. In this regime, the number of superradiant pulses and the temporal intervals between them can be regulated. This makes it feasible to compose a kind of the Morse Code alphabet and, hence, to develop a technique of processing information.Comment: 6 pages, Revtex, 3 figure