Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
в найденном
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>S=spin-waves<.>)
Общее количество найденных документов : 17
Показаны документы с 1 по 10
 1-10    11-17 
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Martynov S. N.
Заглавие : The incommensurate magnetic structure of a tetragonal antiferromagnet with antisymmetric exchange
Место публикации : J. Exp. Theor. Phys. - 2009. - Vol. 109, Is. 6. - P.979-988. - ISSN 1063-7761, DOI 10.1134/S1063776109120097
Примечания : Cited References: 34
Предметные рубрики: FLUCTUATION-INDUCED PHASE
FIELD-INDUCED GAP
COPPER METABORATE
WEAK FERROMAGNETISM
SOLITON LATTICE
SPIN-WAVES
CUB2O4
BA2CUGE2O7
CSCUCL3
CHAINS
Ключевые слова (''Своб.индексиров.''): anti-symmetric--antiferromagnetic sublattices--antiferromagnets--antisymmetric exchange--exchange bonds--ferromagnetic component--ferromagnetic moments--ginzburg-landau functional--incommensurate magnetic structures--mean field approximation--modulation vectors--polarization planes--polarization vectors--symmetry groups--antiferromagnetic materials--antiferromagnetism--crystal orientation--crystal symmetry--ferromagnetic materials--ferromagnetism--magnetic devices--magnetic structure--modulation--polarization--vector spaces--vectors--crystallography
Аннотация: Analysis of the incommensurate magnetic structure that emerges for two coexisting types of the antisymmetric Dzyaloshinski-Moriya exchange interaction (the weakly ferromagnetic component of vector D along the tetragonal axis and the helicoidal component distributed in the tetragonal plane) is carried out for the first time for a tetragonal antiferromagnet. The helicoidal component for each pair of interacting spins has a 2D distribution; its direction in the tetragonal plane depends on the direction of the exchange bond in each pair. The Lifshits invariant of the Ginzburg-Landau functional is obtained, which is responsible for the formation of an incommensurate magnetic structure for such a distribution. It is shown in the mean field approximation that the incommensurate magnetic structure that forms in this case is a nonlinear double helicoid with a modulation vector lying in the tetragonal plane and with a varying angle between the polarization planes of quasi-antiferromagnetic sublattices. The ground state of the magnet is degenerate in the orientation of the modulation vector in the tetragonal plane. The rate of variation in the orientations of moments in the polarization planes passing through the tetragonal axis is controlled by the angle between the directions of the moments and the tetragonal axis. The local weakly ferromagnetic moment remaining in the polarization plane varies in magnitude and sign. The relation between the orientations of the modulation and polarization vectors is derived for the cases of simple and inversion tetragonal axes in the space symmetry group of the crystal.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Martynov S. N.
Заглавие : Antisymmetric Exchange in the CuB2O4 A Subsystem
Место публикации : JETP Letters. - 2009. - Vol. 90, Is. 1. - P.55-58. - ISSN 0021-3640, DOI 10.1134/S0021364009130116
Примечания : Cited References: 31
Предметные рубрики: TRANSVERSE MAGNETIC-FIELD
FLUCTUATION-INDUCED PHASE
COPPER METABORATE
ANTIFERROMAGNETIC CHAINS
SOLITON LATTICE
INDUCED GAP
SPIN-WAVES
BA2CUGE2O7
CSCUCL3
MNSI
Аннотация: The space distribution of the components of the microscopic Hamiltonian of the antisymmetric Dzyaloshinskii-Moriya exchange with respect to the exchange bond pairs of the A subsystem of Cu2+ ions in the crystallographic 4b positions of CuB2O4 has been obtained using symmetry analysis. The possibility of the coexistence of two different types of the exchange spatial distribution is demonstrated. The component of the anti-symmetric exchange vector D parallel to the tetragonal axis has a weakly ferromagnetic distribution for all of the directions of the bonds between the nearest magnetic neighbors. Each exchange bond has an additional component of the antisymmetric exchange parallel to the bond projection on the tetragonal plane. The spatial distribution of these components is helicoidal with the modulation vector in the tetragonal crystal plane.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Mankov Y. I.
Заглавие : Partial restoration of the wave spectrum of a superlattice due to cross correlations between one- and three-dimensional inhomogeneities
Место публикации : Phys. Rev. B: AMERICAN PHYSICAL SOC, 2007. - Vol. 75, Is. 23. - Ст.235422. - ISSN 1098-0121, DOI 10.1103/PhysRevB.75.235422
Примечания : Cited References: 32
Предметные рубрики: ELASTIC MEDIUM THEORY
PERIODIC MULTILAYERS
SPIN-WAVES
LOCALIZATION
SYSTEMS
SUSCEPTIBILITY
DISORDER
MEDIA
Аннотация: Effects of cross correlations between one-dimensional (1D) and three-dimensional (3D) random inhomogeneities on the wave spectrum in sinusoidal superlattices are studied theoretically. The situation when the gap in the spectrum (the forbidden zone) at the first Brillouin zone boundary of the superlattice is closed under the action of the 1D inhomogeneities is considered. The phenomenon of the partial opening of this gap is found when the 3D inhomogeneities cross correlated with the 1D inhomogeneities add to the superlattice. The appearance of the logarithmic resonance in the center of the forbidden zone under the action of the cross correlations is shown. The physical nature of the effects in the wave spectrum of the superlattice that are caused by the cross correlations and the relation of these effects with the asymptotic properties of the correlation function of inhomogeneities are discussed.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Mankov Y. I.
Заглавие : Partial restoration of the wave spectrum of a superlattice due to cross correlations between one- and three-dimensional inhomogeneities
Место публикации : Phys. Rev. B: AMERICAN PHYSICAL SOC, 2007. - Vol. 75, Is. 23. - Ст.235422. - ISSN 1098-0121, DOI 10.1103/PhysRevB.75.235422
Примечания : Cited References: 32
Предметные рубрики: ELASTIC MEDIUM THEORY
PERIODIC MULTILAYERS
SPIN-WAVES
LOCALIZATION
SYSTEMS
SUSCEPTIBILITY
DISORDER
MEDIA
Аннотация: Effects of cross correlations between one-dimensional (1D) and three-dimensional (3D) random inhomogeneities on the wave spectrum in sinusoidal superlattices are studied theoretically. The situation when the gap in the spectrum (the forbidden zone) at the first Brillouin zone boundary of the superlattice is closed under the action of the 1D inhomogeneities is considered. The phenomenon of the partial opening of this gap is found when the 3D inhomogeneities cross correlated with the 1D inhomogeneities add to the superlattice. The appearance of the logarithmic resonance in the center of the forbidden zone under the action of the cross correlations is shown. The physical nature of the effects in the wave spectrum of the superlattice that are caused by the cross correlations and the relation of these effects with the asymptotic properties of the correlation function of inhomogeneities are discussed.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Mankov Y. I.
Заглавие : Effects of cross correlations between 1D and 3D inhomogeneities on the high-frequency susceptibility of superlattices
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2006. - Vol. 102, Is. 4. - P625-635. - ISSN 1063-7761, DOI 10.1134/S106377610604011X
Примечания : Cited References: 29
Предметные рубрики: ELASTIC MEDIUM THEORY
3-DIMENSIONAL INHOMOGENEITIES
PERIODIC MULTILAYERS
SPIN-WAVES
LOCALIZATION
SPECTRUM
SYSTEMS
MEDIA
DISORDER
Ключевые слова (''Своб.индексиров.''): correlation methods--damping--function evaluation--wave equations--brillouin zone--distribution function--random variables--superlattices
Аннотация: Cross Correlations between components of a mixture of one-dimensional (I D) and three-diniensional (3D) inhomogenetics are described by introducing a distribution function taking into account correlations between absolute values of two random variables in the absence of correlations between the variables themselves. This distribution function is used for derivation and analysis of the superlattice correlation function containing a mixture of cross-correlated 1D and 3D in homogeneitics. The effect of such inhomogeneities on the high-frequency susceptibility at the edge of the first Brillouin zone of the superlattice is investigated. It is shown that positive cross correlations partly suppress the effect of a mixture of 1D and 3D inhomogeneities on the wave spectrum: the gap at the boundary of the Brillouin zone increases, and wave damping decreases as compared to the effect produced by a mixture of 1D and 3D inhomogeneities in the absence of cross correlations. Negative cross correlations lead to the opposite effect: the gap decreases and wave damping increases. Cross correlations also lead to the emergence of new resonance effects: a narrow dip or a narrow peak at the center of the band gap (depending on the sign of the correlation factor).
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Mankov Y. I.
Заглавие : Effect of the correlation properties of one- and three-dimensional inhomogeneities on the high-frequency magnetic susceptibility of sinusoidal superlattices
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2005. - Vol. 47, Is. 3. - P587-594. - ISSN 1063-7834, DOI 10.1134/1.1884725
Примечания : Cited References: 29
Предметные рубрики: PERIODIC MULTILAYERS
WAVE SPECTRUM
SPIN-WAVES
LOCALIZATION
SYSTEMS
DISORDER
Аннотация: The effect of one-(1D) and three-dimensional (3D) inhomogeneities on the high-frequency magnetic susceptibility at the boundary of the first Brillouin zone of a ferromagnetic superlattice is studied. The study is performed with an earlier developed method of random spatial modulation (RSM) of the superlattice period. In this method, structural inhomogeneities are described in terms of the random-phase model, in which the phase depends on three coordinates in the general case. The frequency spacing Delta v(m) between two peaks in the imaginary part of the averaged Green's function, which characterizes the gap width in the frequency spectrum at the boundary of the Brillouin zone, is calculated as a function of both the root-mean-square fluctuations gamma(i) and the correlation wavenumbers eta(i) of phase inhomogeneities (i = 1 and 3 for 1D and 3D inhomogeneities, respectively). The function Delta v(m)(gamma(1), eta(1)) for 1D inhomogeneities is shown to be symmetric with respect to inter- changing the variables gamma(1)(2) and eta(1), whereas the function Delta v(m)(gamma(3), eta(3)) for 3D inhomogeneities is strongly asym- metric with respect to interchanging gamma(3)(2) eta(3). This effect is associated with the difference in form between the correlation functions of 1D and 3D inhomogeneities and can be used to determine the dimensionality of inhomogeneities from the results of spectral studies of such superlattices. (c) 2005 Pleiades Publishing, Inc.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Laletin O. N.
Заглавие : Waves in a superlattice with arbitrary interlayer boundary thickness
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2004. - Vol. 46, Is. 12. - P2292-2300. - ISSN 1063-7834, DOI 10.1134/1.1841396
Примечания : Cited References: 34
Предметные рубрики: PERIODIC STRUCTURES
RAYLEIGH-WAVES
LAYERED MEDIUM
ELASTIC-WAVES
SPIN-WAVES
SPECTRUM
MEDIA
PROPAGATION
EXCITATIONS
MULTILAYERS
Аннотация: The transmittance D(omega), reflectance R(omega), and dispersion omega(k) are investigated for waves of various nature propagating through a one-dimensional superlattice (multilayer structure) with arbitrary thickness of the interlayer boundary. The dependences of the band gap widths Deltaomega(m) and their positions in the wave spectrum of the superlattice on the interlayer boundary thickness d and the band number m are calculated. Calculations are performed in terms of the modified coupled-mode theory (MCMT) using the frequency dependence of R(omega), as well as in the framework of perturbation theory using the function omega(k), which made it possible to estimate the accuracy of the MCMT method; the MCMT method is found to have a high accuracy in calculating the band gap widths and a much lower accuracy in determining the gap positions. It is shown that the m dependence of Deltaomega(m) for electromagnetic (or elastic) waves is different from that for spin waves. Furthermore, the widths of the band gaps with m = 1 and 2 are practically independent of d, whereas the widths of all gaps for m 2 depend strongly on d. Experimental measurements of these dependences allow one to determine the superlattice interface thicknesses by using spectral methods. (C) 2004 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Maradudin A. A., Poszdnyakov A. V.
Заглавие : Waves in a superlattice with anisotropic inhomogeneities
Место публикации : JETP Letters. - 2003. - Vol. 78, Is. 9. - P.592-596. - ISSN 0021-3640, DOI 10.1134/1.1641491
Примечания : Cited References: 28
Предметные рубрики: PERIODIC MULTILAYERS
SPIN-WAVES
SPECTRUM
LOCALIZATION
SYSTEMS
MEDIA
DISORDER
AVERAGE
Аннотация: Dependences of the dispersion laws and damping of waves in an initially sinusoidal superlattice on inhomogeneities with anisotropic correlation properties are studied for the first time. The period of the superlattice is modulated by the random function described by the anisotropic correlation function K-phi(r) that has different correlation radii, k(parallel toparallel to)(-1) and k(perpendicular to)(-1), along the axis of the superlattice z and in the plane xy, respectively. The anisotropy of the correlation is characterized by the parameter lambda = 1 - k(perpendicular to)/k(parallel toparallel to) that can change from lambda = 0 to lambda = 1 when the correlation wave number k(perpendicular to) changes from k(perpendicular to) = k(parallel toparallel to) (isotropic 3D inhomogeneities) to k(perpendicular to) = 0 (1D inhomogeneities). The correlation function of the superlattice K(r) is developed. Its decreasing part goes to the asymptote L that divides the correlation volume into two parts, characterized by finite and infinite correlation radii. The dependences of the width of the gap in the spectrum at the boundary of the Brillouin zone Deltanu and the damping of waves xi on the value of lambda are studied. It is shown that decreasing L leads to the decrease of Deltanu, and increase of xi, with the increase of lambda. (C) 2003 MAIK "Nauka / Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Mankov Y. I., Maradudin A. A.
Заглавие : Effects of the dimensionality of inhomogeneities on the wave spectrum of superlattices
Место публикации : Phys. Rev. B: AMERICAN PHYSICAL SOC, 2003. - Vol. 68, Is. 2. - Ст.24209. - ISSN 1098-0121, DOI 10.1103/PhysRevB.68.024209
Примечания : Cited References: 26
Предметные рубрики: ELASTIC MEDIUM THEORY
PERIODIC MULTILAYERS
SPIN-WAVES
LOCALIZATION
SYSTEMS
MEDIA
DISORDER
Аннотация: Dependences of the dispersion laws and damping of waves in an initially sinusoidal superlattice on the dimensionality of inhomogeneities modulating the period of the superlattice are studied. The cases of one- and three-dimensional modulations, as well as modulation by a mixture of inhomogeneities of both of these dimensionalities, are considered. The correlation function of the superlattice K(r) has the form of a product of the same periodic function and a decreasing function that is significantly different for these different cases. For r -- infinity the decreasing function goes to zero for the one-dimensional inhomogeneities and to a nonzero asymptote for the three-dimensional ones. Consequently, the transition from the disordered to ordered states is accompanied in the three-dimensional case not only by an increase of the correlation radius as in the one-dimensional case, but also by a change in the relationship between the volumes of the superlattices with finite and infinite correlation radii. The decreasing part of the correlation function for the mixture of inhomogeneities of different dimensionalities has the form of a product of the decreasing parts of the correlation functions of the components of the mixture. This leads to the nonadditivity of the contributions of the components of different dimensionalities to the resulting modification of the parameters of the wave spectrum that are due to the inhomogeneities (the damping of waves for the mixture of these components is smaller than the sum of the dampings of the components, the maximum gap in the spectrum corresponds to the simultaneous presence of both components, and so on).
WOS,
Читать в сети ИФ
Найти похожие
10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Mankov Y. I., Maradudin A. A.
Заглавие : Effects of the mixture of one- and three-dimensional inhomogeneities on the wave spectrum of superlattices
Место публикации : JETP Letters. - 2003. - Vol. 77, Is. 6. - P.285-290. - ISSN 0021-3640, DOI 10.1134/1.1577758
Примечания : Cited References: 24
Предметные рубрики: PERIODIC MULTILAYERS
SPIN-WAVES
LOCALIZATION
SYSTEMS
THICKNESSES
DISORDER
AVERAGE
MEDIA
Аннотация: Dependences of the dispersion laws and damping of waves in an initially sinusoidal superlattice on the dimensionality of inhomogeneities modulating the period of the superlattice are studied. The cases of one- and three-dimensional modulations, as well as modulation by a mixture of inhomogeneities of both of these dimensionalities, are considered. The correlation function of the superlattice K(r) has the form of a product of the same periodic function and a decreasing function that is significantly different for these different cases. The decreasing part of the correlation function for the mixture of inhomogeneities of different dimensionalities has the form of a product of the decreasing parts of the correlation functions of the components of the mixture. This leads to the nonadditivity of the contributions of the components of different dimensionalities to the resulting modification of the parameters of the wave spectrum that are due to the inhomogeneities (the damping of waves for the mixture of these components is smaller than the sum of the dampings of the components, the maximum gap in the spectrum corresponds to the simultaneous presence of both components of the mixture, not only of the three-dimensional inhomogeneities). (C) 2003 MAIK "Nauka / Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
 1-10    11-17 
 

Другие библиотеки

© Международная Ассоциация пользователей и разработчиков электронных библиотек и новых информационных технологий
(Ассоциация ЭБНИТ)