Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
в найденном
 Найдено в других БД:Каталог книг и брошюр библиотеки ИФ СО РАН (28)
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>K=Functions<.>)
Общее количество найденных документов : 62
Показаны документы с 1 по 20
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Lundin A. A., Zobov V. E.
Заглавие : Asymptotic similarity of time correlation functions and shape of the 13C and 29Si NMR spectra in diamond and silicon
Коллективы : Institute of Chemical Physics of the Russian Academy of Science [0082-2018-0005, TSITIS AAAA-A18-118020690203]
Место публикации : J. Exp. Theor. Phys. - 2018. - Vol. 127, Is. 2. - P.305-315. - ISSN 1063-7761, DOI 10.1134/S1063776118080216. - ISSN 1090-6509(eISSN)
Примечания : Cited References: 47. - We thank V.A. Atsarkin, V.V. Demidov, F.S. Dzheparov, and E. B. Feldman for the discussion of our results. This work was supported by a subsidy allocated by the Institute of Chemical Physics of the Russian Academy of Science for the State assignment, theme 0082-2018-0005, code TSITIS AAAA-A18-118020690203.
Предметные рубрики: SPIN SYSTEMS
LINE-SHAPES
RELAXATION
SOLIDS
PARAMAGNETS
RESONANCE
Аннотация: Based on the proposed theory, we have investigated the shape of the NMR absorption spectra for 13C and 29Si nuclei in diamond and silicon crystals attributable to the internuclear dipole–dipole interaction. In accordance with the available experimental data, we have considered both crystals with a 100% content of magnetoactive isotopes and crystals with a comparatively low dilution by nonmagnetic nuclei. The time correlation functions (the first of which is the Fourier transform of the NMR spectrum) arising in an infinite chain of coupled differential equations are shown to be mutually similar with a slight time delay. The proposed theory allows the spectrum to be calculated analytically. The results obtained agree satisfactorily with the experimental ones. It is noted that the mutual similarity of the time correlation functions is probably a corollary of the development of dynamical chaos in the system.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : ZOBOV V. E.
Заглавие : AUTOCORRELATION FUNCTIONS OF THE ANISOTROPIC HEISENBERG PARAMAGNET IN THE APPROXIMATION OF A SELF-CONSISTENT FLUCTUATING FIELD
Место публикации : Theor. Math. Phys.: PLENUM PUBL CORP, 1990. - Vol. 84, Is. 1. - P751-757. - ISSN 0040-5779, DOI 10.1007/BF01017200
Примечания : Cited References: 10
Предметные рубрики: RELAXATION
Аннотация: The method proposed earlier for investigating the dynamics of the isotropic Heisenberg paramagnet at high temperatures is generalized to the anisotropic case. A system of nonlinear integrodifferential equations relating the three autocorrelation functions of the x, y, and z components of an individual spin is obtained. A solution of the system is sought in the form of series in powers of the time and is investigated on the plane of the complex time variable. The coefficients of the series up to the tenth order for the xy model and the model with truncated dipole interaction are calculated, and the parameters of the singular points nearest the origin are determined from them.
WOS
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Rotter I., Sadreev A. F.
Заглавие : Avoided level crossings, diabolic points, and branch points in the complex plane in an open double quantum dot
Место публикации : Phys. Rev. E: AMERICAN PHYSICAL SOC, 2005. - Vol. 71, Is. 3. - Ст.36227. - ISSN 1063-651X, DOI 10.1103/PhysRevE.71.036227
Примечания : Cited References: 49
Предметные рубрики: BERRY TOPOLOGICAL PHASE
EXCEPTIONAL POINTS
GEOMETRIC PHASES
NUCLEAR REACTIONS
RESONANCE STATES
UNIFIED THEORY
S-MATRIX
CONTINUUM
REPULSION
INTERFEROMETER
Ключевые слова (''Своб.индексиров.''): branch points in the complex plane (bpcp)--diabolic points (dp)--geometric phases--riemann sheets--eigenvalues and eigenfunctions--electron energy levels--functions--hamiltonians--quantum theory--resonance--topology--semiconductor quantum dots
Аннотация: We study the spectrum of an open double quantum dot as a function of different system parameters in order to receive information on the geometric phases of branch points in the complex plane (BPCP). We relate them to the geometrical phases of the diabolic points (DPs) of the corresponding closed system. The double dot consists of two single dots and a wire connecting them. The two dots and the wire are represented by only a single state each. The spectroscopic values follow from the eigenvalues and eigenfunctions of the Hamiltonian describing the double dot system. They are real when the system is closed, and complex when the system is opened by attaching leads to it. The discrete states as well as the narrow resonance states avoid crossing. The DPs are points within the avoided level crossing scenario of discrete states. At the BPCP, width bifurcation occurs. Here, different Riemann sheets evolve and the levels do not cross anymore. The BPCP are physically meaningful. The DPs are unfolded into two BPCP with different chirality when the system is opened. The geometric phase that arises by encircling the DP in the real plane, is different from the phase that appears by encircling the BPCP. This is found to be true even for a weakly opened system and the two BPCP into which the DP is unfolded.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorban A., Popova T., Zinovyev A.
Заглавие : Codon usage trajectories and 7-cluster structure of 143 complete bacterial genornic sequences
Разночтения заглавия :авие SCOPUS: Codon usage trajectories and 7-cluster structure of 143 complete bacterial genomic sequences
Место публикации : Physica A: ELSEVIER SCIENCE BV, 2005. - Vol. 353. - P365-387. - ISSN 0378-4371, DOI 10.1016/j.physa.2005.01.043
Примечания : Cited References: 46
Предметные рубрики: DNA-BASE COMPOSITION
ASYMMETRIC SUBSTITUTION PATTERNS
PROTEIN-CODING REGIONS
MICROBIAL GENOMES
GENE IDENTIFICATION
MARKOV-MODELS
G+C CONTENT
BIAS
PREDICTION
SELECTION
Ключевые слова (''Своб.индексиров.''): genome--cluster--codon usage--correlations--entropy--mean field--cluster--codon usage--correlations--entropy--genome--mean field--approximation theory--correlation methods--database systems--entropy--functions--genes--mathematical models--clusters--codon usage--genomes--mean field--bacteria
Аннотация: Three results are presented. First, we prove the existence of a universal 7-cluster structure in all 143 completely sequenced bacterial genomes available in Genbank in August 2004, and explained its properties. The 7-cluster structure is responsible for the main part of sequence heterogeneity in bacterial genomes. In this sense, our 7 clusters is the basic model of bacterial genome sequence. We demonstrated that there are four basic "pure" types of this model, observed in nature: "parallel triangles", "perpendicular triangles", degenerated case and the flower-like type. Second, we answered the question: how big are the position-specific information and the contribution connected with correlations between nucleotide. The accuracy of the mean-field (context-free) approximation is estimated for bacterial genomes. We show that codon us-age of bacterial genomes is a multi-linear function of their genomic G+C-content with high accuracy (more precisely, by two similar functions, one for eubacterial genomes and the other one for archaea). Description of these two codon-usage trajectories is the third result. All 143 cluster animated 3D-scatters are collected in a database and is made available on our web-site: http://www.ihes.fr/similar to zinovyev/7clusters. (c) 2005 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zobov V. E., Kucherov M. M.
Заглавие : Concentration dependence of the wings of a dipole-broadened magnetic resonance line in magnetically diluted lattices
Место публикации : J. Exp. Theor. Phys.: Maik Nauka-Interperiodica Publishing, 2017. - Vol. 124, Is. 1. - P.151-158. - ISSN 10637761 (ISSN), DOI 10.1134/S106377611615005X
Примечания : Cited References: 34
Ключевые слова (''Своб.индексиров.''): drug interactions--magnetic fields--magnetic resonance--magnetism--nonlinear equations--optical systems--autocorrelation functions--concentration dependence--high-frequency asymptotics--local field approximations--magnetic resonance line--modulation frequencies--strong static magnetic fields--time autocorrelation functions--autocorrelation
Аннотация: The singularities of the time autocorrelation functions (ACFs) of magnetically diluted spin systems with dipole–dipole interaction (DDI), which determine the high-frequency asymptotics of autocorrelation functions and the wings of a magnetic resonance line, are studied. Using the self-consistent fluctuating local field approximation, nonlinear equations are derived for autocorrelation functions averaged over the independent random arrangement of spins (magnetic atoms) in a diamagnetic lattice with different spin concentrations. The equations take into account the specificity of the dipole–dipole interaction. First, due to its axial symmetry in a strong static magnetic field, the autocorrelation functions of longitudinal and transverse spin components are described by different equations. Second, the long-range type of the dipole–dipole interaction is taken into account by separating contributions into the local field from distant and near spins. The recurrent equations are obtained for the expansion coefficients of autocorrelation functions in power series in time. From them, the numerical value of the coordinate of the nearest singularity of the autocorrelation function is found on the imaginary time axis, which is equal to the radius of convergence of these expansions. It is shown that in the strong dilution case, the logarithmic concentration dependence of the coordinate of the singularity is observed, which is caused by the presence of a cluster of near spins whose fraction is small but contribution to the modulation frequency is large. As an example a silicon crystal with different 29Si concentrations in magnetic fields directed along three crystallographic axes is considered. © 2017, Pleiades Publishing, Inc.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : MARTYNOV S. N.
Заглавие : CORRELATION-FUNCTIONS AND ELECTRON-SPIN-RESONANCE LINEWIDTH OF TWO-DIMENSIONAL HEISENBERG MAGNETS
Место публикации : Fiz. Tverd. Tela: MEZHDUNARODNAYA KNIGA, 1986. - Vol. 28, Is. 10. - P3006-3011. - ISSN 0367-3294
Примечания : Cited References: 15
WOS
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : IGNATCHENKO V. A., ISKHAKOV R. S.
Заглавие : CORRELATION-FUNCTIONS OF RANDOM ANISOTROPY AND THE PROBLEM OF FERROMAGNET STATE STABILITY
Место публикации : Journal de Physique. - 1988. - Vol. 49, Is. C-8. - P.1245-1246. - ISSN 0302-0738, DOI 10.1051/jphyscol:19888565
Примечания : Cited References: 8
WOS
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisova L. T., Molokeev M. S., Ryabov V. V., Kargin Y. F., Chumilina L. G., Denisov V. M.
Заглавие : Crystal structure and thermodynamic properties of titanate ErGaTi2O7
Место публикации : Russ. J. Inorg. Chem. - 2021. - Vol. 66, Is. 4. - P.532-537. - ISSN 00360236 (ISSN), DOI 10.1134/S0036023621040082
Примечания : Cited References: 29
Аннотация: Erbium gallium titanate was prepared by solid-phase synthesis via the sequential calcination of precursor oxides in an air atmosphere at 1273 and 1573 K. The crystal structure of ErGaTi2O7 was characterized by full-profile analysis for the X-ray diffraction pattern of the synthesized powder sample as follows: space group Pcnb, a = 9.77326(15) Å, b = 13.5170(2) Å, c = 7.33189(11) Å, V = 918.58(3) Å3, ρ = 6.10 g/cm3. The high-temperature heat capacity of erbium gallium titanate was measured by differential scanning calorimetry within a temperature range of 320–1000 K. Based on these data, the basic thermodynamic functions of ErGaTi2O7 were calculated.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sadreev A. F.
Заглавие : Current statistics for transport through rectangular and circular billiards
Место публикации : Phys. Rev. E: AMER PHYSICAL SOC, 2004. - Vol. 70, Is. 1. - Ст.16208. - ISSN 1539-3755, DOI 10.1103/PhysRevE.70.016208
Примечания : Cited References: 21
Предметные рубрики: ELECTRON-TRANSPORT
QUANTUM CHAOS
NODAL POINTS
RANDOM WAVES
STREAMLINES
Ключевые слова (''Своб.индексиров.''): bessel functions--current density--eigenvalues and eigenfunctions--electric potential--mathematical models--microwaves--parameter estimation--poisson distribution--probability--scattering--gaussian distribution--microwave transmission--resonant transmission--scattering functions--quantum theory
Аннотация: We consider the statistics of currents for electron (microwave) transmission through rectangular and circular billiards. For the resonant transmission the current distribution is describing by the universal distribution [ A. I. Saichev , J. Phys. A 35, L87 (2002) ]. For the more typical case of nonresonant transmission the current statistics reveals features of the current channeling (corridor effect) interior of the billiard. The numerical statistics is compared with analytical distributions.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sadreev A. F., Berggren K. F.
Заглавие : Current statistics for wave transmission through an open Sinai billiard: Effects of net currents
Место публикации : Phys. Rev. E: AMER PHYSICAL SOC, 2004. - Vol. 70, Is. 2. - Ст.26201. - ISSN 1539-3755, DOI 10.1103/PhysRevE.70.026201
Примечания : Cited References: 27
Предметные рубрики: EIGENVECTOR STATISTICS
OPEN SYSTEMS
EIGENFUNCTIONS
CHAOS
FLUCTUATIONS
CROSSOVER
ELECTRONS
INTENSITY
Ключевые слова (''Своб.индексиров.''): acoustic wave transmission--boundary conditions--computer simulation--continuum mechanics--current density--fermi level--mathematical transformations--microwaves--probability density function--quantum theory--random processes--reverberation--statistical methods--surface waves--waveguides--microwave cavities--poynting vector--sinai billiard--wave functions--cavity resonators
Аннотация: Transport through quantum and microwave cavities is studied by analytic and numerical techniques. In particular, we consider the statistics for a finite net probability current (Poynting vector) j flowing through an open ballistic Sinai billiard to which two opposite leads/wave guides are attached. We show that if the net probability current is small, the scattering wave function inside the billiard is well approximated by a Gaussian random complex field. In this case, the current statistics are universal and obey simple analytic forms. For larger net currents, these forms still apply over several orders of magnitudes. However, small characteristic deviations appear in the tail regions. Although the focus is on electron and microwave billiards, the analysis is relevant also to other classical wave cavities as, for example, open planar acoustic reverberation rooms, elastic membranes, and water surface waves in irregularly shaped vessels.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zobov V. E., Lundin A. A.
Заглавие : Decay of multispin multiquantum coherent states in the NMR of a solid
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 112, Is. 3. - P451-459. - ISSN 1063-7761, DOI 10.1134/S1063776111020129
Примечания : Cited References: 24
Предметные рубрики: SYSTEMS
SPECTRA
Ключевые слова (''Своб.индексиров.''): adiabatic approximations--andersons--coherent state--dynamic phenomena--experimental data--local fields--model-based--radiospectroscopy--relaxation functions--spin precession--theoretical result--two-component--coherent light
Аннотация: A model based on the Anderson adiabatic approximation, which is widely used for describing various aspects of dynamic phenomena in conventional radiospectroscopy, is proposed for describing the decay of multispin multiquantum coherent states in a solid. The coherent state relaxation function is represented by the product of two functions corresponding to spin precession in a two-component local field with a correlated and an uncorrelated component. Theoretical results of this study explain the experimental data reported in a number of publications and are in good agreement with these data.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Polukhin D. S.
Заглавие : Development of a self-consistent approximation
Место публикации : J. Phys. A: IOP Publishing, 2016. - Vol. 49, Is. 9. - Ст.095004. - ISSN 17518113 (ISSN), DOI 10.1088/1751-8113/49/9/095004
Примечания : Cited References: 43
Предметные рубрики: SUPERCONDUCTING CRITICAL-TEMPERATURE
LATTICE-VIBRATIONS
VERTEX FUNCTION
ELECTRON
Ключевые слова (''Своб.индексиров.''): self-consistent approximation--green's functions--vertex corrections--inhomogeneities--correlations--dynamic susceptibility
Аннотация: A self-consistent approximation of a higher level than the standard self-consistent approximation, known in various fields of physics as the Migdal, Kraichnan or Born self-consistent approximation, is derived taking into account both the first and second terms of the series for the vertex function. In contrast to the standard approximation, the new self-consistent approximation is described by a system of two coupled nonlinear integral equations for the self-energy and the vertex function. In addition to all the diagrams with non-intersecting lines of correlation/interaction taken into account by the standard self-consistent approximation, the new approach takes into account in each term of the Green's function expansion a significant number of diagrams with intersections of these lines. Because of this, the shape, linewidth, and amplitude of the resonance peaks of the dynamic susceptibility calculated in this approximation are much closer to the exact values of these characteristics. The advantage of the new self-consistent approach is demonstrated by the example of calculation of the dynamic susceptibility of waves in an inhomogeneous medium. © 2016 IOP Publishing Ltd.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Ovchinnikov S. G.
Заглавие : Doping-dependent evolution of low-energy excitations and quantum phase transitions within an effective model for high-T-c copper oxides
Разночтения заглавия :авие SCOPUS: Doping-dependent evolution of low-energy excitations and quantum phase transitions within an effective model for high-T c copper oxides
Место публикации : Eur. Phys. J. B: SPRINGER, 2007. - Vol. 57, Is. 3. - P271-278. - ISSN 1434-6028, DOI 10.1140/epjb/e2007-00179-2
Примечания : Cited References: 49
Предметные рубрики: ELECTRON CORRELATIONS
HUBBARD-MODEL
RANGE-ORDER
DIMENSIONS
WAVE
FERMIONS
SYSTEMS
BANDS
METAL
Ключевые слова (''Своб.индексиров.''): doping dependent evolution--kinematic correlation functions--low energy excitations--quantum phase transitions--doping (additives)--electric excitation--mean field theory--parameter estimation--phase transitions--quantum theory--copper oxides
Аннотация: In this paper a mean-field theory for the spin-liquid paramagnetic non-superconducting phase of the p- and n-type high-T-c cuprates is developed. This theory applied to the effective t-t'-t ''-J* model with the ab initio calculated parameters and with the three-site correlated hoppings. The static spin-spin and kinematic correlation functions beyond Hubbard-I approximation are calculated self-consistently. The evolution of the Fermi surface and band dispersion is obtained for the wide range of doping concentrations x. For p-type systems the three different types of behavior are found and the transitions between these types are accompanied by the changes in the Fermi surface topology. Thus a quantum phase transitions take place at x = 0.15 and at x = 0.23.Due to the different Fermi surface topology we found for n-type cuprates only one quantum critical concentration, x = 0.2. The calculated doping dependence of the nodal Fermi velocity and the effective mass are in good agreement with the experimental data.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Val'kov V. V., Shustin M. S.
Заглавие : Effect of intersite repulsion on the correlation functions and thermodynamics of an Ising chain with annealed magnetic disorder
Место публикации : Bull. Russ. Acad. Sci. Phys.: Allerton Press, 2016. - Vol. 80, Is. 11. - P.1335-1337. - ISSN 10628738 (ISSN), DOI 10.3103/S1062873816110290
Примечания : Cited References: 6. - This work was supported by the Russian Foundation for Basic Research, project nos. 13-02-00073, 14-02-31237, and 15-42-04372.
Ключевые слова (''Своб.индексиров.''): chains--magnetic susceptibility--temperature distribution--thermodynamics--transfer matrix method--correlation function--equilibrium behavior--equilibrium distributions--non-magnetic impurities--quantum phase transitions--repulsion parameter--temperature dependence--transfer matrix technique--phase transitions
Аннотация: An exact solution for a model describing the equilibrium behavior of an ensemble of Ising chains with nonmagnetic intersite repulsion of nearest neighbors and an equilibrium distribution of nonmagnetic impurities is obtained using the transfer matrix technique. The possibility of exciting quantum phase transitions using the intersite repulsion parameter in a system is demonstrated. Proximity to the critical points of these transitions has a substantial effect on the temperature dependence of a system’s magnetic susceptibility. © 2016, Allerton Press, Inc.
Смотреть статью,
Scopus,
Читать в сети ИФ
Найти похожие
15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bulgakov E. N., Maksimov D. N., Sadreev A. F.
Заглавие : Electric circuit networks equivalent to chaotic quantum billiards
Место публикации : Phys. Rev. E: AMERICAN PHYSICAL SOC, 2005. - Vol. 71, Is. 4. - Ст.46205. - ISSN 1063-651X, DOI 10.1103/PhysRevE.71.046205
Примечания : Cited References: 31
Предметные рубрики: TIME-REVERSAL SYMMETRY
CONDUCTANCE FLUCTUATIONS
STATISTICS
SYSTEMS
EIGENFUNCTIONS
DOTS
Ключевые слова (''Своб.индексиров.''): chaotic quantum billiards--electric resonance circuits (erc)--resonance networks--wave functions--boundary conditions--capacitors--chaos theory--eigenvalues and eigenfunctions--electric inductors--natural frequencies--quantum theory--resonance--statistical mechanics--networks (circuits)
Аннотация: We consider two electric RLC resonance networks that are equivalent to quantum billiards. In a network of inductors grounded by capacitors, the eigenvalues of the quantum billiard correspond to the squared resonant frequencies. In a network of capacitors grounded by inductors, the eigenvalues of the billiard are given by the inverse of the squared resonant frequencies. In both cases, the local voltages play the role of the wave function of the quantum billiard. However, unlike for quantum billiards, there is a heat power because of the resistance of the inductors. In the equivalent chaotic billiards, we derive a distribution of the heat power which describes well the numerical statistics.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Slobodchikov, Anatoly A., Nekrasov, Igor A., Begunovich L. V., Makarov I. A., Korshunov M. M., Ovchinnikov S. G.
Заглавие : Electronic structure and minimal models for flat and corrugated CuO monolayers: An ab initio study
Место публикации : Materials. - 2023. - Vol. 16, Is. 2. - Ст.658. - ISSN 1996-1944 (ISSN), DOI 10.3390/ma16020658
Примечания : Cited References: 24. - This research was in part funded by the Russian Science Foundation grant number 23-22-00372
Аннотация: CuO atomic thin monolayer (mlCuO) was synthesized recently. Interest in the mlCuO is based on its close relation to CuO2 layers in typical high temperature cuprate superconductors. Here, we present the calculation of the band structure, the density of states and the Fermi surface of the flat mlCuO as well as the corrugated mlCuO within the density functional theory (DFT) in the generalized gradient approximation (GGA). In the flat mlCuO, the Cu-3dx2−y2 band crosses the Fermi level, while the Cu-3dxz,yz hybridized band is located just below it. The corrugation leads to a significant shift of the Cu-3dxz,yz hybridized band down in energy and a degeneracy lifting for the Cu-3dx2−y2 bands. Corrugated mlCuO is more energetically favorable than the flat one. In addition, we compared the electronic structure of the considered CuO monolayers with bulk CuO systems. We also investigated the influence of a crystal lattice strain (which might occur on some interfaces) on the electronic structure of both mlCuO and determined the critical strains of topological Lifshitz transitions. Finally, we proposed a number of different minimal models for the flat and the corrugated mlCuO using projections onto different Wannier functions basis sets and obtained the corresponding Hamiltonian matrix elements in a real space.
Смотреть статью,
WOS,
Читать в сети ИФ
Найти похожие
17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zobov V. E., Kucherov M. M.
Заглавие : Exponential Bound for the Heating Rate of Periodically Driven Spin Systems
Место публикации : J. Exp. Theor. Phys. - 2019. - Vol. 128, Is. 4. - P.641-649. - ISSN 1063-7761, DOI 10.1134/S1063776119030130. - ISSN 1090-6509(eISSN)
Примечания : Cited References: 42
Предметные рубрики: AUTOCORRELATION FUNCTIONS
HEISENBERG PARAMAGNET
FLUCTUATION SPECTRUM
Аннотация: For the nuclear spin system of a solid in the presence of an inhomogeneous magnetic field, we have found a rigorous bound for the heating rate of the system under the action of a high-frequency magnetic field, which is applied, for example, to create effective Hamiltonians. We consider the autocorrelation function (ACF) of a spin rotating in a local field whose fluctuations are specified by a Gaussian random process. The correlation function of a random field is taken as the sum of a static inhomogeneous contribution and a time-dependent contribution expressed self-consistently via the spin ACF. The ACF singularities on the imaginary time axis whose coordinates determine the exponents of exponential asymptotics in the high-frequency domain are investigated. The dependences of the coordinates on field inhomogeneity for various approximations have been derived. The wing of the ACF spectrum in the cumulant approximation is shown to serve as a rigorous upper bound for the wing of the ACF spectrum and, consequently, for the heating rate of the system when subjected to variable magnetic fields. We have established that randomly distributed inhomogeneous magnetic fields increase the wings of the ACF spectra and, thus, speed up the system's heating.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bulgakov E. N., Pichugin K. N., Sadreev A. F.
Заглавие : Giant resonant enhancement of optical binding of dielectric disks
Место публикации : J. Opt. Soc. Am. B. - 2020. - Vol. 37, Is. 11. - P.3335-3340. - ISSN 07403224 (ISSN), DOI 10.1364/JOSAB.402659
Примечания : Cited References: 30. - Russian Science Support Foundation (19-02-00055)
Аннотация: Two-fold variation over the aspect ratio of each disk and distance between disks gives rise to numerous events of avoided crossing of resonances of individual disks. For these events, the hybridized anti-bonding resonant modes can acquire a morphology close to the Mie resonant mode with the high orbital momentum of an equivalent sphere. The factor of such resonance can exceed the factor of an isolated disk by two orders of magnitude. We show that dual incoherent counterpropagating coaxial Bessel beams with power 1mW/µm2 with frequency resonant to such anti-bonding Mie-like modes result in unprecedented optical binding forces up to tens of nano-Newtons for silicon micrometer-sized disks. We show also that the magnitude and sign of optical forces depend strongly on the longitudinal wave vector of the Bessel beams.
Смотреть статью,
Читать в сети ИФ,
Scopus,
WOS
Найти похожие
19.

Вид документа : Статья из сборника (выпуск продолж. издания)
Шифр издания :
Автор(ы) : Ignatchenko V. A., Polukhin D. S.
Заглавие : Green's functions of polaritons in a medium with zero-mean inhomogeneous coupling parameter
Коллективы : International Conference on Photonics of Nano- and Bio-Structures, International Conference on Photonics of Nano- and Bio-Structures
Место публикации : Physics Procedia: Elsevier, 2017. - Vol. 86. - P.117-121. - , DOI 10.1016/j.phpro.2017.01.031
Примечания : Cited References: 10
Ключевые слова (''Своб.индексиров.''): electromagnetic waves--optical phonons--crossing resonance--polaritons--green's functions--self-consistent approximation
Аннотация: Dynamic susceptibilities (Green's functions) of the interacting electromagnetic waves G”e(ω) and optical phonons G”u(ω) in a medium with zero-mean inhomogeneous coupling parameter have been considered. The calculation was performed using a self-consistent approximation for the two stochastically interacting wave fields. It is shown that on the tops of the resonance maxima of the imaginary parts of the Green functions the fine structure is formed: a minimum (dip) on the top of G”e(ω) and narrow maximum (peak) on the top of G”u(ω). With increasing the correlation wavenumber of inhomogeneities kc (i.e., with decreasing the size of inhomogeneities), the width of the peak on G”u(ω) decreases, and two resonance maxima in the function G”e(ω) are formed. Because of the large difference in the speeds of light and optical phonons, the fine structure of the polaritons is manifested itself more clearly and saved to a much larger values of kc, than for the studied earlier crossing resonance of spin and elastic waves.
Смотреть статью,
Scopus,
Читать в сети ИФ
Найти похожие
20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ignatchenko V. A., Tsikalov D. S.
Заглавие : Green's functions of the scalar model of electromagnetic fields in sinusoidal superlattices
Место публикации : Physica B: Elsevier, 2016. - Vol. 485. - P.94-102. - ISSN 09214526 (ISSN), DOI 10.1016/j.physb.2016.01.006
Примечания : Cited References: 30
Предметные рубрики: SCATTERING
MEDIA
PROPAGATION
GRATINGS
DENSITY
LIGHT
Ключевые слова (''Своб.индексиров.''): green's functions--electromagnetic waves--scalar model--sinusoidal superlattices--photonic crystals--ldos
Аннотация: Problems of obtaining Green's function and using it for studying the structure of scalar electromagnetic fields in a sinusoidal superlattice are considered. An analytical solution of equation in the k-space for Green's function is found. Green's function in the r-space is obtained by both the numerical and the approximate analytical Fourier transformation of that solution. It is shown, that from the experimental study of Green's function in the k-space the position of the plane radiation source relative to the extremes of the dielectric permittivity ?(z) can be determined. The relief map of Green's function in the r-space shows that the structure of the field takes the form of chains of islets in the plane ?z, the number of which increases with increasing the distance from a radiation source. This effect leads to different frequency dependences of Green's function at different distances from the radiation source and can be used to measure the distance to the internal source. The real component of Green's function and its spatial decay in the forbidden zones in the near field is investigated. The local density of states, depending on the position of the source in the superlattice, is calculated.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
 

Другие библиотеки

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