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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Кузьмин, Валерий Ипполитович, Николаев, Сергей Викторович
Заглавие : Исследование аномалий электронной дисперсии в модели Хаббарда, t-J- и t-J*-модели в рамках кластерной теории возмущений в представлении Х-операторов
Коллективы : Сибирский молодежный семинар по высокотемпературной сверхпроводимости и физике наноструктур – ОКНО 2014 (X; 13 - 14 ноября 2014 г.; Новосибирск)
Место публикации : Вестник НГУ. Физика. - 2015. - Т. 10, Вып. 1. - С. 50-56. - ISSN 1818-7994
Примечания : Библиогр.: 23. - Работа выполнена при финансовой поддержке Российского научного фонда (проект № 14-12-00061).
Ключевые слова (''Своб.индексиров.''): высокотемпературная сверхпроводимость--электронная структура купратов--высокоэнергетические кинки--кластерные теории--модель хаббарда--t-j-модель--high-temperature superconductivityory--electronic structure of cuprates--high-energy kinks--cluster perturbation theory--hubbard model--t-j-model
Аннотация: В рамках кластерной теории возмущений в представлении Х-операторов Хаббарда рассчитана энергетическая структура электронов в модели Хаббарда, t-J- и t-J *-модели с учетом уширения спектральных линий, соответствующего экспериментам по фотоэмиссионной спектроскопии с угловым разрешением. При энергиях порядка интеграла перескока t в полученных спектрах наблюдаются аномалии, схожие с высокоэнергетическими кинками, наблюдаемыми в экспериментах по фотоэмиссионной спектроскопии с угловым разрешением. Исследовано поведение высокоэнергетических аномалий электронной дисперсии при изменениях величины допирования и параметра кулоновского отталкивания. Проанализировано влияние трехцентровых коррелированных перескоков на результаты расчета.The electronic structure with the spectral line broadening corresponding to the angle-resolved photoemission spectroscopy resolution has been calculated for the Hubbard model, t-J and t-J * models within the norm-conserving cluster perturbation theory. The electronic dispersion anomalies similar to the high-energy kinks observed in the angle-resolved photoemission spectroscopy experiments are obtained at the energy scale of order of the hopping integral t. The doping dependence of the high-energy anomalies for different Coulomb repulsion values is discussed. The influence of the three-site correlated hopping on the results is analyzed.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Su B., Jin J., Peng Y., Molokeev M. S., Yang X., Xia Z.
Заглавие : Zero-Dimensional Organic Copper(I) Iodide Hybrid with High Anti-Water Stability for Blue-Light-Excitable Solid-State Lighting
Место публикации : Adv. Opt. Mater. - 2022. - Vol. 10, Is. 12. - Ст.2102619. - ISSN 21951071 (ISSN), DOI 10.1002/adom.202102619
Примечания : Cited References: 55. - This work was supported by the National Natural Science Foundation of China (Nos.: 51961145101 and 51972118), Guangzhou Science & Technology Project (202007020005), and the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01×137). This work was also funded by RFBR according to the research Project No.19-52-80003
Аннотация: The discovery of rare-earth free luminescent materials with blue-light-excitable characteristic is of great importance for solid-sate lighting applications. Herein, a Cu(I)-based 0D luminescent hybrid (1,3-dppH2)2Cu4I8∙H2O is synthesized by a facile solution method, and it shows the orange-red emission peaking at 625 nm upon 460 nm excitation. The structure-related luminescence mechanism has been elaborated by experimental and theoretical investigations. Moreover, the emission intensity remains unchanged even after continuous water treatment for 60 days due to the improved structural stability originating from intermolecular π–π interaction between organic cations. A warm white light-emitting diode (LED) device with the color rendering index of 91.4% has been fabricated by combining the 440 nm LED chip, green-emitting Lu3Al5O12:Ce3+, and (1,3-dppH2)2Cu4I8∙H2O. This work provides a new design route towards 0D cuprous halide materials and will initiate more exploration of their intrinsic luminescence mechanism.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Yurkin G. Yu., Patrin G. S., Velikanov D. A., Beletsky V. V.
Заглавие : Transport properties of FeSi with cobalt impurities
Место публикации : TRENDS IN MAGNETISM. - 2011. - Vol. 168-169. - С. 493-496. - ISSN 10120394 (ISSN); 9783037850213 (ISBN), DOI 10.4028/www.scientific.net/SSP.168-169.493
Ключевые слова (''Своб.индексиров.''): iron monosilicide--kondo effect--magnetization--resistivity--spindependent scattering--superparamagnetic cluster--cobalt--crystals--electric resistance--electron energy loss spectroscopy--kondo effect--magnetic field effects--magnetic properties--magnetization--magnetoresistance--scattering--superparamagnetism--transport properties--cobalt--electric conductivity--electron scattering--impurities--kondo effect--magnetism--magnetization--experimental investigations--kondo models--magnetoresistance properties--resistivity--si crystals--spin dependent scattering--superparamagnetic clusters--crystal impurities--crystal impurities
Аннотация: The results of experimental investigations of Fe1-xCo xSi crystals in the impurity limit are presented in this article. We made an attempt to study changes of magnetic properties and conductivity in mixed Fe1-xCoxSi crystals in the impurity limit. Magnetoresistance properties are well described in the framework of Kondo model. The presence of Co-subsystem leads to the occurrence of spin-dependent channel in electron scattering conduction.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zinenko V. I.
Заглавие : Thermodynamics of spin ice on an antiperovskite lattice in the cluster approximation
Колич.характеристики :5 с
Место публикации : Phys. Solid State. - 2023. - Vol. 65, Is. 7. - P.1203-1207. - ISSN 10637834 (ISSN), DOI 10.21883/PSS.2023.07.56415.63. - ISSN 10906460 (eISSN)
Примечания : Cited References: 9
Аннотация: Low-temperature thermodynamic properties of spin ice have been studied for compounds with the structure of antiperovskite containing rare-earth ions with the general chemical formula ReMeO (where Re - is a rare-earth element, Me - is a divalent metal). The calculations were carried out in the cluster approximation. The cases of undistorted and distorted ORe6 octahedron are discussed. In the case of an undistorted octahedron in the absence of an external magnetic field, the ground state of the system is infinitely degenerate. When an external magnetic field is applied, anomalies in the temperature dependences of heat capacity, entropy and magnetization are detected. In the case of a distorted octahedron and assuming that this distortion leads to the energy efficiency of two of the sixty-four configurations, it is obtained that there is a phase transition in the system of magnetic rare-earth ions.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zinenko V. I., Pavlovskii M. S.
Заглавие : Thermodynamics of spin ice in staggered and direct (along the [111] axis) fields in the cluster approximation
Коллективы : Russian Foundation for Basic Research; Government of the Krasnoyarsk Territory; Krasnoyarsk Territory Foundation for Supporting the Scientific and Research Activity [16-42-243039]
Место публикации : J. Exp. Theor. Phys.: MAIK Nauka-Interperiodica / Springer, 2017. - Vol. 124, Is. 2. - P.295-303. - ISSN 1063-7761, DOI 10.1134/S1063776117020182. - ISSN 1090-6509(eISSN)
Примечания : Cited References:15. - This work was supported by the Russian Foundation for Basic Research, the Government of the Krasnoyarsk Territory, and the Krasnoyarsk Territory Foundation for Supporting the Scientific and Research Activity (project no. 16-42-243039).
Предметные рубрики: ENTROPY
HEAT
Аннотация: We have analyzed the low-temperature thermodynamic properties of spin ice in the staggered and direct (acting along the [111] axis) fields for rare-earth oxides with the chalcolamprite structure and general formula Re23+Me24+O72- . Calculations have been performed in the cluster approximation. The results have been compared with experimental temperature dependences of heat capacity and entropy for Dy2Ti2O7 compound for different values of the external field in the [111] direction. The experimental data and calculated results have also been compared for the Pr2Ru2O7 compound with the antiferromagnetic ordering of magnetic moments of ruthenium ions, which gives rise to the staggered field acting on the system of rare-earth ions. The calculated temperature dependences of heat capacity and entropy are in good agreement with experimental data.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : VAKS V. G., ZINENKO V. I.
Заглавие : THERMODYNAMICS OF 6-VERTEX MODELS IN DIRECT AND STAGGERED ELECTRIC-FIELDS IN THE CLUSTER APPROXIMATION
Разночтения заглавия :авие SCOPUS: Thermodynamics of six-vertex models in direct and staggered electric fields in the cluster approximation
Место публикации : JOURNAL OF PHYSICS C-SOLID STATE PHYSICS: IOP PUBLISHING LTD, 1986. - Vol. 19, Is. 17. - P3083-3104. - ISSN 0022-3719, DOI 10.1088/0022-3719/19/17/007
Примечания : Cited References: 21
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Komogortsev S. V., Iskhakov R. S., Zimin A. A., Filatov E. Y., Korenev S. V., Shubin Yu. V., Chizhik N. A., Yurkin G. Yu., Eremin E. V.
Заглавие : The exchange interaction effects on magnetic properties of the nanostructured CoPt particles
Место публикации : J. Magn. Magn. Mater.: Elsevier, 2016. - Vol. 401. - P.236-241. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2015.10.041
Примечания : Cited References: 55. - The work has been partially supported by RFBR Grants 15-08-06673, 14-03-00411, 14-03-00129, 15-42-0417115 and it is partly performed in Siberian Federal University within the state contract of the Russian Federation Ministry of Education and Science for 2014-2016 (project number 1792)
Предметные рубрики: CLUSTER BEAM DEPOSITION
BULK MAGNETS
NANOCRYSTALLINE FERROMAGNETS
REMANENCE ENHANCEMENT
THIN-FILMS
COERCIVITY
MICROSTRUCTURE
NANOPARTICLES
IRON
SYSTEM
Аннотация: Various manifestations of the exchange interaction effects in magnetization curves of the CoPt nanostructured particles are demonstrated and discussed. The inter-grain exchange constant A in the sponge-like agglomerates of crystallites is estimated as A=(7±1) pJ/m from the approach magnetization to saturation curves that is in good agreement with A=(6.6±0.5) pJ/m obtained from Bloch T 3/2 law. The fractal dimensionality of the exchange coupled crystallite system in the porous media of the disordered CoPt alloy d=(2.60±0.18) was estimated from the approach magnetization to saturation curve. Coercive force decreases with temperature as Hc~T 3/2 which is assumed to be a consequence of the magnetic anisotropy energy reduction due to the thermal spin wave excitations in the investigated CoPt particles. © 2015 Elsevier B.V. All rightsreserved.Демонстрируются и обсуждаются различные проявления эффектов обменного взаимодействия в кривых намагниченности наноструктуированных частиц CoPt. Межзеренная обменная константа А в агломератах губчатой структуры кристаллитов оценивается как /A/=(7±1) pJ/m из кривых приближения намагниченности к насыщению, это значение находится в хорошем согласии с /A/=(6.6±0.5) pJ/m, полученным из закона /T/. /2 Блоха. Размерность фрактала обменно-соединенных кристаллических систем в пористой среды неупорядоченного сплава CoPt /d/=(2.60±0.18) оценивалась из кривых приближения намагниченности к насыщению. Коэрцитивная сила уменьшается с температурой по закону /H_c /~/T/. /2 , который, как предполагается, есть следствие уменьшения энергии магнитной анизотропии из-за теплового возбуждения спиновых волн в изучаемых частицах CoPt.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zinenko V. I.
Заглавие : The cluster investigation of the q-state potts-model
Место публикации : Phys. Status Solidi B. - 1982. - Vol. 114, Is. 2. - P.695-703. - ISSN 0370-1972, DOI 10.1002/pssb.2221140248
Примечания : Cited References: 26
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gritsenko, C.h., Dzhun I., Volochaev M. N., Gorshenkov M., Babaytsev G., Chechenin N., Sokolov A. Е., Tretiakov, Oleg A., Rodionova V.
Заглавие : Temperature-dependent magnetization reversal in exchange bias NiFe/IrMn/NiFe structures
Коллективы : Russian Foundation for Basic Research (RFBR) [17-32-50170]; MEXT, Japan [17 K05511, 17H05173]; Center for Science and Innovation in Spintronics (Core Research Cluster), Tohoku University; JSPS; RFBR under the Japan-Russian Research Cooperative Program; Ministry of Education and Science of the Russian Federation [3.9002.2017/6.7]
Место публикации : J. Magn. Magn. Mater. - 2019. - Vol. 482. - P.370-375. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2019.03.044. - ISSN 1873-4766(eISSN)
Примечания : Cited References: 55. - Ch. G. and M. G. acknowledge financial support by the Russian Foundation for Basic Research (RFBR grant. 17-32-50170). Ch. G. acknowledges the 5 top 100 Russian Academic Excellence Project at the Immanuel Kant Baltic Federal University. O.A.T. acknowledges support by the Grants-in-Aid for Scientific Research (Grant Nos. 17 K05511 and 17H05173) from MEXT, Japan, by the grant of the Center for Science and Innovation in Spintronics (Core Research Cluster), Tohoku University, by JSPS and RFBR under the Japan-Russian Research Cooperative Program. V.R. acknowledges the Ministry of Education and Science of the Russian Federation in the framework of government assignment 3.9002.2017/6.7. Electron microscopy examination was carried out at the Center for Collective Use of the Krasnoyarsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences. We also thank Montserrat Rivas for helpful discussions.
Предметные рубрики: COERCIVITY
FILM
ROUGHNESS
THICKNESS
HEADS
IRMN
Аннотация: We demonstrate magnetization reversal features in NiFe/IrMn/NiFe thin-film structures with 40% and 75% relative content of Ni in Permalloy in the temperature range from 80 K to 300 K. The magnetization reversal sequence of the two ferromagnetic layers is found to depend on the type of NiFe alloy. In the samples with 75% relative content of Ni, the bottom ferromagnetic layer reverses prior to the top one. On the contrary, in the samples with 40% of Ni, the top ferromagnetic layer reverses prior to the bottom one. These tendencies of magnetization reversal are preserved in the entire range of temperatures. These distinctions can be explained by the morphological and structural differences of interfaces in the samples based on two types of Permalloy.
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shaykhutdinov K. A., Balaev D. A., Gokhfeld D. M., Kuzmin Y. I., Popkov S. I., Petrov M. I.
Заглавие : Study of current-voltage characteristics of Bi-based high-temperature superconductors with fractal cluster structure
Коллективы : International Workshop on Weak Superconductivity
Место публикации : Physica C. - 2006. - Vol. 435, Is. 1-2. - P.19-22. - ISSN 0921-4534, DOI 10.1016/j.physc.2006.01.010
Примечания : Cited References: 18
Предметные рубрики: NORMAL-PHASE
VORTEX MOTION
TRANSPORT
Ключевые слова (''Своб.индексиров.''): superconducting foam--pinning--critical current density--fractal--percolation--cluster--cluster--critical current density--fractal--percolation--pinning--superconducting foam--bismuth--critical current density (superconductivity)--electric currents--electric potential--foams--percolation (solid state)--polycrystalline materials--cluster--fractal--pinning--superconducting foam--superconducting materials
Аннотация: We study the effect of the structure on critical currents and current-voltage characteristics (CVC's) of foamed bismuth-based polycrystalline high-temperature superconductors (HTSC). The fractal cluster structure of superconducting foams has been observed and the fractal dimension of boundaries between superconducting and normal clusters has been determined. Based on the magnetic and transport properties of the foamed polycrystalline superconductors, we have shown that the initial parts of CVC's of the superconducting foams are described well by the model that accounts the magnetic flux trapping in fractal clusters of a normal phase. (c) 2006 Elsevier B.V. All rights reserved.
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Chudin O. S., Verpekin V. V., Vasiliev A. D., Rubaylo A. I.
Заглавие : Structure of a trinuclear μ3-vinylidene cluster CpMnFePt(μ3-C=CHPh)(PPh3)(CO)6
Место публикации : J. Struct. Chem. - 2017. - Vol. 58, Is. 3. - P.600-602. - ISSN 00224766 (ISSN), DOI 10.1134/S0022476617030234
Примечания : Cited References: 15
Ключевые слова (''Своб.индексиров.''): heterometallic clusters--iron--manganese--platinum--single crystal x-ray diffraction analysis--vinylidene complexes
Аннотация: The single crystal X-ray diffraction study of the heterometallic cluster CpMnFePt(μ3-C=CHPh)(PPh3)(CO)6 is performed. The crystallographic characteristics are as follows: a = 32.356(15) Å, b = 11.754(5) Å, c = 20.114(9) Å, β = 115.707(6)°, V = 6893(5) Å3, space group C2/c, Z = 8, dcalc = 1.741 g/cm3. The cluster molecule contains a bridging phenylvinylidene ligand coordinated to a metallic core in the form of a Mn–Fe–Pt chain (the Mn–Fe and Fe–Pt bond lengths are 2.6768(14) Å and 2.6280(11) Å respectively and the Mn⋯Pt distance is 3.6425(19) Å).
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Nikolaev S. V., Korshunov M. M.
Заглавие : Spin and charge susceptibilities of the two-orbital model within the cluster perturbation theory for Fe-based materials
Место публикации : J. Supercond. Nov. Magn.: Springer, 2016. - Vol. 29, Is. 12. - P.3093-3097. - ISSN 15571939 (ISSN), DOI 10.1007/s10948-016-3784-8
Примечания : Cited References: 40. - We acknowledge partial support by RFBR (grants 12-02-31534, 13-02-01395, and 16-02-00098), and Government Support of the Leading Scientific Schools of the Russian Federation (NSh-7559.2016.2).
Ключевые слова (''Своб.индексиров.''): fe-based superconductors--mutiorbital models--cluster perturbation theory
Аннотация: Cluster perturbation theory is used to calculate band structure, spectral functions, Fermi surface, and spin and charge susceptibilities for the two-orbital model of iron pnictides with the on-site multiorbital Hubbard interactions. Susceptibilities are calculated within the approximation combining the cluster perturbation theory for the self-energy corrections and the random-phase approximation (RPA) for the vertex renormalizations. Calculations for the small values of Hubbard repulsion U ≤ 2 eV confirm that the rigid band approximation and RPA for the spin and charge susceptibilities are suitable approaches for the case of weak interactions. © 2016, Springer Science+Business Media New York.
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kudashkin K., Nikolaev S. V., Ovchinnikov S. G.
Заглавие : Spectral properties of the Bose-Hubbard model within the cluster perturbation theory in X-operators representation
Коллективы : RFBR [16-02-00098, 16-42-243048, 16-42-240511, 16-42-240769]; Government of Krasnoyarsk Territory; Russian President Grant [NSh-7559.2016.2]
Место публикации : J. Supercond. Nov. Magn.: Springer, 2017. - Vol. 30, Is. 1. - P.103-107. - ISSN 1557-1939, DOI 10.1007/s10948-016-3781-y. - ISSN 1557-1947(eISSN)
Примечания : Cited References:16. - This work was supported by RFBR grant 16-02-00098, Government of Krasnoyarsk Territory and RFBR according to the research projects 16-42-243048, 16-42-240511, and 16-42-240769, and the Russian President Grant NSh-7559.2016.2.
Предметные рубрики: TRANSITION
SUPERFLUID
INSULATOR
ATOMS
Ключевые слова (''Своб.индексиров.''): bose-hubbard model--ultracold gases--cluster perturbation theory--density of states--spectral properties
Аннотация: We study the two-dimensional ultracold Bose gas in optical lattice. We use cluster perturbation theory based on Hubbard X-operators to calculate the spectral function and phase diagram of Bose-Hubbard model which is minimal model to describe behavior of ultracold gases in optical lattices. We have analyzed spectral properties of spinless bosons in a square lattice taking into account the short-range correlation.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S., Petrakovskii G. A., Miroshnichenko N. I.
Заглавие : Simulation of magnetic properties of the two-dimensional magnetic with anisotropic antiferromagnetic interactions and cluster ordering by quantum Monte Carlo
Место публикации : Phys. Lett. A: ELSEVIER SCIENCE BV, 2008. - Vol. 372, Is. 26. - P4722-4725. - ISSN 0375-9601, DOI 10.1016/j.physleta.2008.05.010
Примечания : Cited References: 12
Предметные рубрики: SPIN SYSTEM
EXCITATIONS
CU3B2O6
MODEL
Ключевые слова (''Своб.индексиров.''): anisotropic antiferromagnetic--cluster ordering--plateau of magnetization--modulated structure--exchange in cu3b2o6--anisotropic antiferromagnetic--cluster ordering--exchange in cu3b2o6--modulated structure--plateau of magnetization
Аннотация: Magnetic with anisotropic anti ferromagnetic exchange interactions and special topology of coupling in the square lattice with spins pairs ordering is studied by quantum Monte Carlo method. The antiferromagnetic order is found to be more stable as compared to spin liquid state. Exchange interactions and wave vector of structure modulation for Cu3B2O6 is estimated. Neel temperature versus strength of exchange in spin pair is calculated. Plateau and modulation of magnetic structure in field magnetization dependence is revealed. (C) 2008 Elsevier B.V. All rights reserved.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Glamazda, A. Yu., Gnezdilov V. P., Lemmens P., Zvyagina G. A., Gudim I. A.
Заглавие : Raman scattering study of the rare-earth binary ferroborate Nd0.75Dy0.25Fe3(BO3)4 single crystal
Коллективы : DFG Excellence Cluster Quantum FrontiersGerman Research Foundation (DFG) [EXC 2123-390837967, DFG Le967/16-1, DFG-RTG 1952/1]
Место публикации : Low Temp. Phys. - 2021. - Vol. 47, Is. 12. - P.1011-1021. - ISSN 1063-777X, DOI 10.1063/10.0007074. - ISSN 1090-6517(eISSN)
Примечания : Cited References: 25. - A. Yu. Glamazda thanks Dr. A. V. Peschanskii for fruitful discussions. P. Lemmens acknowledges funding by the DFG Excellence Cluster Quantum Frontiers, EXC 2123-390837967, DFG Le967/16-1, and DFG-RTG 1952/1
Предметные рубрики: MAGNETIC PHASE-TRANSITIONS
SPIN REORIENTATION
Аннотация: We report comprehensive Raman scattering measurements on a single crystal of binary ferroborate Nd0.75Dy0.25Fe3(BO3)4 in the temperature range of 7–295 K with 532 nm (18797 cm−1) laser excitation. The performed analysis of the polarized Raman spectra revealed the bands assigned to phonon, magnetic, and electronic excitations. The temperature evolution of these quasiparticle excitations has allowed us to ascertain the intricate coupling and interplay between lattice, magnetic, and electronic degrees of freedom. Analysis of the measured Raman spectra made it possible to identify all A1 and E phonon modes predicted by the group-theoretical analysis. The splitting energies between the LO and TO components of the polar E phonons were determined. Below the magnetic ordering temperature of the Fe sublattice, TN, we have revealed a multiple peaked two-magnon excitation. Analyzing the temperature evolution of low-frequency modes in the spectra, we also identified modes that are associated with electronic transitions between the crystal field levels of the Nd3+ ions with ground-state 4I9/2 and of the Dy3+ ions with ground-state 6H15/2 multiplets. In addition to the already known temperatures of magnetic transitions, analysis of the temperature behavior of low-frequency phonon and electronic excitations made it possible to establish a temperature T* = 100 K, presumably associated with local distortions of the crystal lattice. The presence of this temperature is confirmed by our ultrasonic study. A group of intense bands observed in the frequency range 1700–2200 cm−1 has been associated with the mixed low-lying electronic Raman transitions 4I9/2→4I11/2 and the high-energy luminescence ones 4G5/2+2G7/2→4I9/2 for the Nd3+ ion.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Orlov Yu. S., Dudnikov V. A.
Заглавие : Polaron model of a pseudogap state in quasi-one-dimensional systems
Место публикации : J. Exp. Theor. Phys. - 2017. - Vol. 125, Is. 5. - P.798-809. - ISSN 10637761 (ISSN), DOI 10.1134/S1063776117110103
Примечания : Cited References: 57. - This work was supported by the Russian Foundation for Basic Research (project nos. 17-02-00826, 16-02-00507, 16-02-00098, and 16-02-00273), by the Government of the Krasnoyarsk krai, by the Kras-noyarsk Regional Foundation for Supporting Scientific and Technological Activity (project nos. 16-42-243048, 16-42-240746, and 16-43-240505)), and by the Grants Council of the President of the Russian Federation (project nos. SP-1844.2016.1 and NSh-7559.2016.2).
Ключевые слова (''Своб.индексиров.''): basic concepts--cluster perturbation theories--polaron models--pseudogap state--quasi-one dimensional--quasi-one-dimensional systems
Аннотация: A brief overview of the basic concepts and problems of the physics of quasi-one-dimensional (q1D) compounds is given. A consistent theoretical description of the nature of the so-called pseudogap state still remains the main problem. A simplified model of the pseudogap state based on the formation of smallradius polarons is considered within the cluster perturbation theory.
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Syed B., Prudnikova S. V., Perianova O. V., Zharkov S. M., Kuzmin A., Chouhan R. S., Potkina N. K., Khohlova O. Y., Lobova T. I., Singh M.
Заглавие : Phytogenic Synthesis of Ag Bionano-Antibiotics Against ESKAPE Drug Resistant Communities in Krasnoyarsk, Siberia
Место публикации : J. Cluster Sci. - 2019. - Vol. 30, Is. 3. - P.589-597. - ISSN 10407278 (ISSN) , DOI 10.1007/s10876-019-01518-7
Примечания : Cited References: 44. - uthors are thankful for facilities provided by Siberian Federal University to carry out the present study. Authors are grateful to Krasnoyarsk Medical University for providing opportunity to carry out the present study.
Аннотация: The present study reports synthesis of silver nano-antibiotics from aqueous extract of H. dissectum. The nano-antibiotics were characterized using UV–visible spectra which displayed maximum absorbance at 430 nm. The role of phytocomponents as reducing agent and stabilization of silver nano-antibiotics was depicted with Fourier-transform infrared spectroscopy which revealed presence of hydroxyl and carboxyl groups associated with silver nano-antibiotics. The crystalline nature was studied with X-ray diffraction which showed Bragg’s intensities at 2θ angle which denoted (101), (111), (200), (220), (311) planes. The morphological characteristics were studied using Transmission Electron Microscopy to reveal the size ranging from 5 to 50 nm. The bactericidal activity of nano-antibiotics was studied via well diffusion and minimal inhibitory concentration assay against members of drug-resistant communities bearing resistant to more than ten standard antibiotics. Nano-antibiotics displayed highest activity against Ps. aeruginosa strain 55 and Methicillin-resistant Staphylococcus aureus with 16 mm zone of inhibition followed by Kl. pneumoniae strain 104 and E. coli strain 55. Moderate activity was observed against Ac. baumannii strains with 12 mm zone of inhibition. The obtained results envision the role of plant mediated nano-antibiotics as one of the best suited alternatives towards combating drug resistant pathogens.
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18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kuz'min V. I., Nikolaev S. V., Korshunov M. M., Ovchinnikov S. G.
Заглавие : One- and two-particle correlation functions in the cluster perturbation theory for cuprates
Место публикации : Materials. - 2023. - Vol. 16, Is. 13. - Ст.4640. - ISSN 19961944 (eISSN), DOI 10.3390/ma16134640
Примечания : Cited References: 63. - V.I.K. and S.V.N. acknowledge support from the Krasnoyarsk Regional Science Foundation and Russian Science Foundation, grant no. 22-22-20007We acknowledge useful discussions with E.I. Shneyder
Аннотация: The physics of high-Tc superconducting cuprates is obscured by the effect of strong electronic correlations. One way to overcome this problem is to seek an exact solution at least within a small cluster and expand it to the whole crystal. Such an approach is at the heart of cluster perturbation theory (CPT). Here, we developed CPT for the dynamic spin and charge susceptibilities (spin-CPT and charge-CPT), with the correlation effects explicitly taken into account by the exact diagonalization. We applied spin-CPT and charge-CPT to the effective two-band Hubbard model for the cuprates obtained from the three-band Emery model and calculated one- and two-particle correlation functions, namely, a spectral function and spin and charge susceptibilities. The doping dependence of the spin susceptibility was studied within spin-CPT and CPT-RPA, that is, the CPT generalization of the random phase approximation (RPA). In the underdoped region, both our methods resulted in the signatures of the upper branch of the spin excitation dispersion with the lowest excitation energy at the (π,π) wave vector and no presence of low-energy incommensurate excitations. In the high doping region, both methods produced a low energy response at four incommensurate wave vectors in qualitative agreement with the results of the inelastic neutron scattering experiments on overdoped cuprates.
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19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Markel V. A., Shalaev V. M., Poliakov E. Y., George T. F.
Заглавие : Numerical studies of second- and fourth-order correlation functions in cluster-cluster aggregates in application to optical scattering
Место публикации : Phys. Rev. E: AMERICAN PHYSICAL SOC, 1997. - Vol. 55, Is. 6. - P7313-7333. - ISSN 1063-651X, DOI 10.1103/PhysRevE.55.7313
Примечания : Cited References: 21
Предметные рубрики: DIFFUSION-LIMITED AGGREGATION
COLLOIDAL AGGREGATION
FRACTAL CLUSTERS
ANTICORRELATION
SIMULATIONS
Аннотация: Two- and four-point density correlation functions p(2)(r) and p(4)(r) are studied numerically and theoretically in computer-generated three-dimensional lattice cluster-cluster aggregates (CCA) with the number of particles N up to 20 000 in application to the light scattering problem. The ''pure'' aggregation algorithm is used, where subclusters of all possible sizes are allowed to collide. We find that large CCA clusters demonstrate pronounced multiscaling. In particular, the fractal dimension determined from the slope of p(2)(r) at small distances differs from that found from the dependence of the radius of gyration on the number of monomers (according to our data, 1.80 and 1.94, respectively). We also consider different functional forms for p(2) and their general properties and applicability. We find that the best fit to the numerical data is provided by the generalized exponential cutoff function with coefficients depending on N. The latter dependence is a manifestation of multiscaling. We propose some theoretical approaches for calculating p(4)(r), assuming p(2)(r) is known. In particular, we find the small-r asymptote for the p(4)(r) and verify it numerically. In addition, we find that p(4)(r) cannot be represented by a scaling dependence with a cutoff function, like p(2)(r) Instead, p(4)(r) is given by an expansion in terms of integer powers of r(2D-3), where D is the fractal dimension (approximate to 1.8 for CCA clusters).
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G., Korshunov M. M., Nikolaev S., Shneyder E. I., Krinitsyn A.
Заглавие : Normal and superconducting properties of cuprates in multielectron theory
Место публикации : J. Supercond. Nov. Magn. - 2013. - Vol. 26, Is. 9. - P.2831-2835. - ISSN 1557-1939, DOI 10.1007/s10948-013-2263-8
Ключевые слова (''Своб.индексиров.''): cluster perturbation theory--fermi surface reconstruction--strong electron correlations
Аннотация: We consider the doping dependence of the normal and superconducting properties of La2-x Srx CuO4 in the low energy effective model based on the ab initio LDA+GTB calculations. We have found that two quantum phase transitions (QPT) of the Lifshitz type correspond well to the experimental phase diagram. For superconducting state, we have considered both magnetic and phonon mechanisms of pairing. Finally, we compare the true Fermi surface and the spectral intensity map seen in ARPES within a new norm conserving cluster perturbation theory (NC-CPT). В© 2013 Springer Science+Business Media New York.
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