Библиотека института физики им. Л.В. Киренского СО РАН

Главная

Базы данных

Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Каталог книг и брошюр библиотеки ИФ СО РАН

Каталог журналов библиотеки ИФ СО РАН

Труды сотрудников ИФ СО РАН

Область поиска

в найденном

Формат представления найденных документов:
полный	информационный	краткий

Отсортировать найденные документы по:
автору	заглавию	году издания	типу документа

Поисковый запрос: (<.>S=DENSITY<.>)

Общее количество найденных документов : 21
Показаны документы с 1 по 20

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Avramov P. V., Sakai S., Entani S., Matsumoto Y., Naramoto, Hiroshi
Заглавие : Ab initio LC-DFT study of graphene, multilayer graphenes and graphite
Место публикации : Chem. Phys. Lett.: Elsevier Science BV, 2011. - Vol. 508, Is. 1-3. - P.86-89. - ISSN 0009-2614, DOI 10.1016/j.cplett.2011.04.016
Примечания : Cited References: 32. - This work was supported by JAEA Research fellowship (P.V.A.). P.V.A. also acknowledges JAEA ASRC and Molecular Spintronics Group for hospitality and fruitful collaboration.
Предметные рубрики: DENSITY
NANORIBBONS
PERFORMANCE
FUNCTIONALS
FULLERENE
COBALT
FILMS
Аннотация: Atomic structure of graphene, bi-, tri-, tetralayer graphenes and graphite as well was studied using ab initio HSE, LDA and PBE DFT approaches in periodic boundary conditions. Based on comparison of theoretical results with experimental data the performance of the methods was estimated. It was found that long-range corrected HSE potential is the most reliable DFT approximation to reproduce the atomic structure of weakly bound multilayer graphenes and graphite as well. (C) 2011 Elsevier B. V. All rights reserved.
WoS,
Scopus,
Смотреть статью,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Altin S., Gokhfeld D. M.
Заглавие : Magnetization loops and pinning force of Bi-2212 single-crystal whiskers
Место публикации : Physica C. - 2011. - Vol. 471, Is. 7-8. - P.217-221. - ISSN 0921-4534, DOI 10.1016/j.physc.2011.01.006
Примечания : Cited References: 40. - The work is supported by Project No. 7 of RAS Program "Quantum physics of condensed matter", Grant No. 13 of Lavrentyev competition of young researchers of SB RAS and Scientific and Technical Research Council of Turkey (TUBITAK) under Contract No. TUBITAK-109T747.
Предметные рубрики: T-C SUPERCONDUCTORS
HIGH-TEMPERATURE SUPERCONDUCTORS
JOSEPHSON VORTICES
GROWTH
BI2SR2CACU2O8+DELTA
DENSITY
STATE
FIELD
MELT
Ключевые слова (''Своб.индексиров.''): bi-2212--whisker--magnetization loop--pinning force--extended critical state model--bi-2212--extended critical state model--magnetization loop--pinning force--whisker--bi-2212--extended critical state model--magnetization loop--pinning force--whisker--flux pinning--magnetic fields--magnetization--critical current density (superconductivity)
Аннотация: Dependence of magnetization on applied magnetic field for single-crystal Bi-2212 whiskers was measured at different temperatures. Symmetric and asymmetric magnetization loops were successfully described by the extended critical state model (the extended Valkov-Khrustalev model). Pinning force of whiskers was investigated. (C) 2011 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Ovchinnikov S. G., Gavrichkov V. A., Nekrasov I. A., Pchelkina Z. V., Anisimov V. I.
Заглавие : Application of the new LDA plus GTB method for the band structure calculation of n-type cuprates
Разночтения заглавия :авие SCOPUS: Application of the new LDA+GTB method for the band structure calculation of n-type cuprates
Место публикации : Physica B: ELSEVIER SCIENCE BV, 2006. - Vol. 378-80: International Conference on Strongly Correlated Electron Systems (SECES 05) (JUL 26-30, 2005, Vienna, AUSTRIA). - P459-460. - ISSN 0921-4526, DOI 10.1016/j.physb.2006.01.340
Примечания : Cited References: 11
Предметные рубрики: SUPERCONDUCTIVITY
PARAMETERS
DENSITY
Ключевые слова (''Своб.индексиров.''): strongly correlated electron systems--superconductivity--n-type cuprates--n-type cuprates--strongly correlated electron systems--superconductivity--electronic structure--hamiltonians--mathematical models--oxide superconductors--perturbation techniques--intercluster hopping--n-type cuprates--strongly correlated electron systems--band structure
Аннотация: A novel hybrid scheme is proposed and applied for band structure calculations of undoped n-type cuprate Nd2CuO4. The ab initio LDA calculation is used to obtain single electron and Coulomb parameters of the multiband Hubbard-type model. In strong correlation regime the electronic structure within this model is calculated by the generalized tight-binding (GTB) method, that combines the exact diagonalization of the model Hamiltonian for a small cluster with perturbation treatment of the intercluster hopping and interactions. For Nd2CuO4, this scheme results in charge transfer insulator with value of the gap and band dispersion in agreement to the experimental data. (c) 2006 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sorokin P. B., Ovchinnikov S. G., Avramov P. V., Chernozatonskii L.A., Fedorov D.G.
Заглавие : Atypical quantum confinement effect in silicon nanowires
Место публикации : J. Phys. Chem. A. - WASHINGTON: AMER CHEMICAL SOC, 2008. - Vol. 112, Is. 40. - С. 9955-9964. - OCT 9. - ISSN 1089-5639, DOI 10.1021/jp805069b
Примечания : Cited Reference Count: 25. - Гранты: This work was in part partially supported by a CREST (Core Research for Evolutional Science and Technology) grant in the Area of High Performance Computing for Multiscale and Multiphysics Phenomena from the Japan Science and Technology Agency (JST) as well as by Russian Fund of Basic Researches (grant 08-02-01096) (L.A.C.). P.V.A. acknowledges the encouragement of Dr. Keiji Morokuma, Research Leader at Fukui Institute for Fundamental Chemistry. The geometry of all presented structures was visualized by ChemCraft software.SUP25/SUP L.A.C. acknowledges I. V. Stankevich for help and fruitful discussions. P.B.S. is grateful to the Joint Supercomputer Center of the Russian Academy of Sciences for access to a cluster computer for quantum-chemical calculations.Финансирующая организация: Japan Science and Technology Agency (JST); Russian Fund of Basic Researches [08-02-01096]
Предметные рубрики: ELECTRONIC-STRUCTURE
OPTICAL-PROPERTIES
SI
DENSITY
WIRES
EXCHANGE
ATOMS
DOTS
Ключевые слова (''Своб.индексиров.''): electric wire--energy gap--gallium alloys--mathematical models--nanostructured materials--nanostructures--nanowires--quantum confinement--quantum electronics--semiconductor quantum dots--silicon--ami methods--band gaps--blue shifts--dinger equations--linear junctions--monotonic decreases--quantum confinement effects--quantum dots--semiempirical--silicon nanowires--system sizes--theoretical models--nanocrystalline silicon--nanowire--quantum dot--silicon--article--chemistry--electron--quantum theory--electrons--nanowires--quantum dots--quantum theory--silicon
Аннотация: The quantum confinement effect (QCE) of linear junctions of silicon icosahedral quantum dots (IQD) and pentagonal nanowires (PNW) was studied using DFT and semiempirical AM1 methods. The formation of complex IQD/PNW structures leads to the localization of the HOMO and LUMO on different parts of the system and to a pronounced blue shift of the band gap; the typical QCE with a monotonic decrease of the band gap upon the system size breaks down. A simple one-electron one-dimensional Schrodinger equation model is proposed for the description and explanation of the unconventional quantum confinement behavior of silicon IQD/PNW systems. On the basis of the theoretical models, the experimentally discovered deviations from the typical QCE for nanocrystalline silicon are explained.
WOS,
Scopus,
eLibrary
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Luna-Acosta G. A., Mendez-Bermudez J. A., Seba P., Pichugin K. N.
Заглавие : Classical versus quantum structure of the scattering probability matrix: Chaotic waveguides
Место публикации : Phys. Rev. E: AMER PHYSICAL SOC, 2002. - Vol. 65, Is. 4. - Ст.46605. - ISSN 1539-3755, DOI 10.1103/PhysRevE.65.046605
Примечания : Cited References: 47
Предметные рубрики: SEMICLASSICAL CROSS-SECTION
CONDUCTANCE FLUCTUATIONS
S-MATRIX
BALLISTIC-TRANSPORT
WEAK-LOCALIZATION
CAVITIES
COLLISIONS
MICROSTRUCTURES
DENSITY
CHANNEL
Ключевые слова (''Своб.индексиров.''): chaos theory--matrix algebra--optical waveguides--quantum theory--scattering--wave equations--chaotic cavities--chaotic waveguides--quantum structure--scattering probability matrix--quantum optics
Аннотация: The purely classical counterpart of the scattering probability matrix (SPM) \S(n,m)\(2) of the quantum scattering matrix S is defined for two-dimensional quantum waveguides for an arbitrary number of propagating modes M. We compare the quantum and classical structures of \S(n,m)\(2) for a waveguide with generic Hamiltonian chaos. It is shown that even for a moderate number of channels, knowledge of the classical structure of the SPM allows us to predict the global structure of the quantum one and, hence, understand important quantum transport properties of waveguides in terms of purely classical dynamics. It is also shown that the SPM, being an intensity measure, can give additional dynamical information to that obtained by the Poincare maps.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Ovchinnikov S. G., Nekrasov I. A., Kokorina E. E., Pchelkina Z. V.
Заглавие : Comparison of the single-electron and many-electron mechanisms of the concentration dependence of the HTSC cuprate band structure
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2007. - Vol. 49, Is. 11. - P2052-2057. - ISSN 1063-7834, DOI 10.1134/S1063783407110066
Примечания : Cited References: 12. - This work was supported by the Russian Foundation for Basic Research (project nos. 05-02-16301, 05-02-17244, 06-02-90537) and the Ural Division of the Russian Academy of Sciences (interdisciplinary project no. 74, programs “Quantum Macrophysics” and “Strongly Correlated Electrons in Semiconductors,Metals, Superconductors, and Magnetic Materials”). Z.P. and I.N. are grateful to the “Dynasty” Foundation, the International Center for Fundamental Physics (Moscow), and the Russian Science Support Foundation for support. I.N. is grateful to the Council on Grants from the President of the Russian Federation for support (grant no. MK-2118.2005.02)
Предметные рубрики: DENSITY
Аннотация: The band structure of the Nd2-xCexCuO4 HTSC is calculated using the LDA+GTB method, which combines the local density approximation (LDA) and the generalized tight-binding (GTB) method. Two mechanisms of the concentration dependence of the band structure (single-electron and many-electron mechanisms) are taken into account. It is demonstrated that the main contribution to the evolution of the band structure with doping comes from the many-electron mechanism.
WOS,
Scopus,
РИНЦ,
Смотреть статью,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Efremov D. V., Korshunov M. M., Dolgov O. V., Golubov A. A., Hirschfeld P. J.
Заглавие : Disorder-induced transition between s(+/-) and s(++) states in two-band superconductors
Разночтения заглавия :авие SCOPUS: Disorder-induced transition between sВ± and s++ states in two-band superconductors
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2011. - Vol. 84, Is. 18. - Ст.180512. - ISSN 1098-0121, DOI 10.1103/PhysRevB.84.180512
Примечания : Cited References: 31. - The authors are grateful to S.-L. Drechsler, P. Fulde, I. I. Mazin, V. Mishra, and D. J. Scalapino for useful discussions. The present work was partially supported by the DFG Priority Programme SPP1458 (D.V.E.), Dutch FOM(A.A.G.), DOEDE-FG02-05ER46236 (P.J.H. and M.M.K.), and RFBR 09-02-00127, Presidium of RAS program N5.7, FCP GK P891, and GK 16.740.12.0731, and President of Russia MK-1683.2010.2 (M.M.K.). P.J.H. and M.M.K. are grateful for the support of the Kavli Institute for Theoretical Physics and the Stanford Institute for Materials & Energy Science during the writing of this work.
Предметные рубрики: HIGH-TEMPERATURE SUPERCONDUCTIVITY
IMPURITIES
DENSITY
Аннотация: We have reexamined the problem of disorder in two-band superconductors, and shown, within the framework of the T-matrix approximation, that the suppression of T-c can be described by a single parameter depending on the intraband and interband impurity scattering rates. T-c is shown to be more robust against nonmagnetic impurities than would be predicted in the trivial extension of Abrikosov-Gor'kov theory. We find a disorder-induced transition from the s(+/-) state to a gapless and then to a fully gapped s(++) state, controlled by a single parameter-the sign of the average coupling constant (lambda). We argue that this transition has strong implications for experiments.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Korshunov M. M., Gavrichkov V. A., Ovchinnikov S. G., Nekrasov I. A., Kokorina E. E., Pchelkina Z. V.
Заглавие : Dominance of many-body effects over the one-electron mechanism for band structure doping dependence in Nd2-xCexCuO4: the LDA + GTB approach
Разночтения заглавия :авие SCOPUS: Dominance of many-body effects over the one-electron mechanism for band structure doping dependence in Nd2-xCexCuO4: The LDA+GTB approach
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2007. - Vol. 19, Is. 48. - Ст.486203. - ISSN 0953-8984, DOI 10.1088/0953-8984/19/48/486203
Примечания : Cited References: 36
Предметные рубрики: NARROW ENERGY BANDS
HUBBARD-MODEL
SUPERCONDUCTORS
DENSITY
TEMPERATURE
ORBITALS
WAVE
Ключевые слова (''Своб.индексиров.''): antiferromagnetism--band structure--correlation methods--crystal structure--local density approximation--superconducting materials--electronic correlations--fermionic quasiparticles--neodymium compounds
Аннотация: In the present work we report band structure calculations for the high-temperature superconductor Nd2-xCexCuO4 in the regime of strong electronic correlations within an LDA + GTB method, which combines the local density approximation (LDA) and the generalized tight-binding method (GTB). The two mechanisms of band structure doping dependence were taken into account. Namely, the one-electron mechanism provided by the doping dependence of the crystal structure, and the many-body mechanism provided by the strong renormalization of the fermionic quasiparticles due to the large on-site Coulomb repulsion. We have shown that, in the antiferromagnetic and in the strongly correlated paramagnetic phases of the underdoped cuprates, the main contribution to the doping evolution of the band structure and Fermi surface comes from the many-body mechanism.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gavrichkov V. A., Ovchinnikov S. G., Borisov A. A., Goryachev E. G.
Заглавие : Evolution of the band structure of quasiparticles with doping in copper oxides on the basis of a generalized tight-binding method
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 2000. - Vol. 91, Is. 2. - P369-383. - ISSN 1063-7761, DOI 10.1134/1.1311997
Примечания : Cited References: 45
Предметные рубрики: T-J MODEL
CUPRATE SUPERCONDUCTORS
ELECTRONIC-STRUCTURE
EXCITATIONS
DEPENDENCE
TEMPERATURE
DERIVATION
SR2CUO2CL2
SPECTRUM
DENSITY
Аннотация: Two methods for stabilizing the two-hole B-3(1g) state as the ground state instead of the Zhang-Rice singlet are determined on the basis of an orthogonal cellular basis for a realistic multiband pd model of a CuO2 layer and the dispersion relations for the valence band top in undoped and doped cases are calculated. In the undoped case, aside from the valence band, qualitatively corresponding to the experimental ARPES data for Sr2CuO2Cl2 and the results obtained on the basis of the t-t'-J model, the calculations give a zero-dispersion virtual level at the valence band top itself. Because of the zero amplitude of transitions forming the virtual level the response corresponding to it is absent in the spectral density function. In consequence, the experimental ARPES data do not reproduce its presence in this antiferromagnetic undoped dielectric. A calculation of the doped case showed that the virtual level transforms into an impurity-type band and acquires dispersion on account of the nonzero occupation number of the two-hole states and therefore should be detected in ARPES experiments as a high-energy peak in the spectral density. The computed dispersion dependence for the valence band top is identical to the dispersion obtained by the Monte Carlo method, and the ARPES data for optimally doped Bi2Sr2CaCu2O8 + delta samples. The data obtained also make it possible to explain the presence of an energy pseudogap at the symmetric X point of the Brillouin band of HTSC compounds. (C) 2000 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fedorov A. S., Sorokin P. B., Kuzubov A. A.
Заглавие : Ab initio study of hydrogen chemical adsorption on platinum surface/carbon nanotube join system
Место публикации : Phys. Status Solidi B. - 2008. - Vol. 245, Is. 8. - P.1546-1551. - ISSN 0370-1972, DOI 10.1002/pssb.200844155
Примечания : Cited References: 31
Предметные рубрики: WALLED CARBON NANOTUBES
MOLECULAR-DYNAMICS
ROOM-TEMPERATURE
STORAGE
ENERGY
THERMODYNAMICS
GRAPHITE
DENSITY
POINTS
Аннотация: The process of hydrogen chemical adsorption on platinum cluster/single wall carbon nanotube (CNT) join surfaces is modelled at various temperatures and pressures. For that, the adsorption energy of hydrogen atoms on surfaces of both platinum (111) plate and CNT (5,5) or (8,8) types is calculated by density functional theory with the PBE approximation. At various temperatures the hydrogen atom hopping rate on both platinum and CNT surfaces is calculated by the transition state theory. Furthermore the hydrogen hopping rate from the platinum surface to the attached nanotube is obtained by calculation of the total energy profile. It is proved that hydrogen atoms can migrate easily at the platinum surface at all temperatures, but at the CNT surface they can migrate beginning at 400-500 K. By calculation of chemical potentials of hydrogen in gas or on CNT or platinum cluster surfaces the equilibrium density of adsorbed hydrogen was calculated at different temperatures and pressures. It is established that for all temperatures in the range 300-900 K and for all pressures less than 500 bar, the hydrogen is dissociated and chemically adsorbed on the platinum surface very effectively, but surface site occupation by hydrogen on attached CNT surface is rather small. But if CNT vacancies are present in the tube structure and the temperature is lower then 450 K, hydrogen atoms can be adsorbed effectively enough on these vacancies. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Frolov G. I.
Заглавие : Magnetic properties of 3d-metal nanocrystalline films
Место публикации : Tech. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2004. - Vol. 49, Is. 7. - P909-915. - ISSN 1063-7842, DOI 10.1134/1.1778867
Примечания : Cited References: 34
Предметные рубрики: ULTRAFINE GRAIN-STRUCTURE
SIZE DEPENDENCE
FERROMAGNETS
COERCIVITY
SYSTEMS
DENSITY
Аннотация: The problem of designing high-resistivity soft magnetic materials based on 3d-metal nanocrystalline films is discussed. To increase the electrical resistivity, nanogranular composites are proposed; they consist of superparamagnetic particles embedded into a dielectric matrix. To obtain the required soft magnetic properties in such composites, it is necessary to realize magnetic ordering due to the effects of magnetic interaction between nanoparticles. As an example, magnetic films that exhibit good high-frequency properties in a range up to several hundreds of megahertz are presented. (C) 2004 MAIK "Nauka / Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

12.

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

13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Balaev D. A., Gokhfeld D. M., Popkov S. I., Shaikhutdinov K. A., Klinkova L. A., Zherikhina L. N., Tsvokhrebov A. M.
Заглавие : Increase in the magnetization loop width in the Ba0.6K0.4BiO3 superconductor: Possible manifestation of phase separation
Место публикации : J. Exp. Theor. Phys.: MAIK Nauka-Interperiodica / Springer, 2014. - Vol. 118, Is. 1. - P.104-110. - ISSN 1063-7761, DOI 10.1134/S1063776114010038. - ISSN 1090-6509
Примечания : Cited References: 39
Предметные рубрики: (K,BA)BIO3 SINGLE-CRYSTALS
II SUPERCONDUCTORS
BISMUTH-OXIDE
PEAK
DENSITY
TC
Аннотация: The magnetization of Ba0.6K0.4BiO3 samples in fields up to 90 kOe in the temperature range from 2 to 30 K is investigated. It is shown that the observed increase in the width of the magnetization loop can be explained by a decrease in the phase nonuniformity upon an increase in the magnetic field. The asymmetric hysteretic dependence of magnetization with the secondary peak was successfully described by the extended critical state model taking into account the phase separation in the superconductor.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kagan M. Y., Valkov V. V.
Заглавие : Anomalous resistivity and superconductivity in the two-band Hubbard model with one narrow band (Review)
Место публикации : Low Temp. Phys. - 2011. - Vol. 37, Is. 1. - P.69-82. - ISSN 1063-777X, DOI 10.1063/1.3552118; \b Физика низких температур
Примечания : Cited References: 62. - We thank A.S. Alexandrov, A.F. Andreev, M.A. Baranov, Yu. Bichkov, A.V. Chubukov, D.V. Efremov, A.S. Hewson, K.A. Kikoin, F.V. Kusmartsev, P. Nozieres, T.M. Rice, A.O. Sboychakov, P. Thalmeer, C.M. Varma, D. Vollhardt, P. Woelfle, A. Yaresko and, especially, P. Fulde, Yu. Kagan, K.I. Kugel, and N.V. Prokof'ev for many simulating discussions on this subject and acknowledge the financial support of RFBR grants # 08-02-00224 and 08-02-00212. M.Yu.K. is also grateful to the Leverhulme trust for a grant to visit Loughborough University, where this work was completed.
Предметные рубрики: FERMI-LIQUID BEHAVIOR
MAGNETIC-ALLOYS
HEAVY
DENSITY
SYSTEMS
STATE
UPT3
MECHANISM
PARTICLE
VALENCE
Аннотация: We search for marginal Fermi-liquid behavior in the two-band Hubbard model with one narrow band. We consider the limit of low electron densities in the bands and strong intraband and interband Hubbard interactions. We analyze the influence of electron-polaron effects and other mechanisms for mass-enhancement (related to the momentum dependence of the self-energies) on the effective mass and scattering times of light and heavy components in the clean case (electron-electron scattering and no impurities). We find a tendency towards phase separation (towards negative partial compressibility of heavy particles) in the 3D case with a large mismatch between the densities of heavy and light bands in the strong coupling limit. We also find that for low temperatures and equal densities, the resistivity in a homogeneous state R(T) proportional to T-2 behaves as a Fermi-liquid in both 3D and 2D. For temperatures greater than the effective bandwidth for heavy electrons T W-h*, the coherence of the heavy component breaks down completely. The heavy particles move diffusively in the surrounding light particles. At the same time, light particles scatter on heavy particles as if on immobile (static) impurities. Under these conditions, the heavy component is marginal, while the light component is not. The resistivity approaches saturation for T W-h* in the 3D case. In 2D the resistivity has a maximum and a localization tail owing to weak-localization corrections of the Altshuler-Aronov type. This behavior of resistivity in 3D could be relevant for some uranium-based heavy-fermion compounds such as UNi2Al3 and in 2D, for some other mixed-valence compounds, possibly including layered manganites. We also consider briefly the superconductive (SC) instability in this model. The leading instability tends to p-wave pairing and is governed by an enhanced Kohn-Luttinger mechanism for SC at low electron densities. The critical temperature corresponds to the pairing of heavy electrons via polarization of the light electrons in 2D. (C) 2011 American Institute of Physics. [doi:10.1063/1.3552118]
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kagan M. Y., Mitskan V. A., Korovushkin M. M.
Заглавие : High-Tc and Low-Tc superconductivity in electron systems with repulsion
Коллективы : Russian Foundation for Basic Research [14-02-00058, 14-02-31237]; Basic Research Program of the National Research University Higher School of Economics; Dynasty foundation; [SP-1361.2015.1]
Место публикации : J. Supercond. Nov. Magn.: Springer, 2016. - Vol. 29, Is. 4. - P.1043-1048. - ISSN 1557-1939, DOI 10.1007/s10948-016-3384-7. - ISSN 1557-1947(eISSN)
Примечания : Cited References:31. - The authors are grateful to V. V. Val'kov, I. S. Burmistrov, M. V. Feigel'man, and A. Ya. Tzalenchuk for valuable remarks. This work is supported by the Russian Foundation for Basic Research (nos. 14-02-00058 and 14-02-31237). One of the authors (M. Yu. K.) gratefully acknowledges support from the Basic Research Program of the National Research University Higher School of Economics. Another one (M. M. K.) thanks the scholarship SP-1361.2015.1 of the President of Russia and the Dynasty foundation.
Предметные рубрики: Fermion systems
Doped graphene
Hubbard-model
Phase-diagram
Superfluidity
Density
Ключевые слова (''Своб.индексиров.''): unconventional superconductivity--kohn-luttinger mechanism--graphene
Аннотация: We demonstrate the instability of the normal state of purely repulsive fermionic systems towards the transition to the Kohn-Luttinger superconducting state. We construct the superconducting phase diagrams of these systems in the framework of the Hubbard and Shubin-Vonsovsky models on the square and hexagonal lattices. We show that an account for the long-range Coulomb interactions, as well as the Kohn- Luttinger renormalizations, lead to an increase in the critical superconducting temperatures in various materials, such as high-temperature superconductors, idealized monolayer, and bilayer of doped graphene. Additionally, we discuss the role of the structural disorder and the nonmagnetic impurities in superconducting properties of real graphene systems.
Смотреть статью,
WOS,
Читать в сети ИФ
Найти похожие

16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gokhfel'd D. M., Balaev D. A., Semenov S. V., Petrov M. I.
Заглавие : Magnetoresistance anisotropy and scaling in textured high-temperature superconductor Bi1.8Pb0.3Sr1.9Ca2Cu3Ox
Место публикации : Phys. Solid State: MAIK Nauka-Interperiodica / Springer, 2015. - Vol. 57, Is. 11. - P.2145-2150. - ISSN 1063-7834, DOI 10.1134/S1063783415110128
Примечания : Cited References: 29
Предметные рубрики: ELECTRIC-POWER APPLICATIONS
TRANSPORT CRITICAL-CURRENT
T-C
SINGLE-CRYSTALS
TAPES
DISSIPATION
BOUNDARIES
DENSITY
FIELD
Аннотация: The magnetoresistance of the textured high-temperature superconductor (HTSC) Bi1.8Pb0.3Sr1.9Ca2Cu3Ox + Ag has been studied at different directions of the transport current I and external magnetic field H with respect to crystallographic directions of HTSC crystallites. When I and H are oriented along the ab planes of crystallites and φ is the angle between H and I, the anisotropic part of the magnetoresistance follows the functional dependence sin2φ, which is characteristic of vortex flows under Lorentz forces. The magnetoresistance R at H parallel to the c axis of crystallites (H || c) is higher than R at H || ab for both cases of I || c and I || ab. The anisotropy coefficient γ ≈ 2.3 has been estimated from the scaling of the dependences R(H) measured at H || c and H || ab. The inclusion of the magnetic field induced by the transport current allows scaling of the dependences R(H) at different values of I. A qualitative picture of the current flow along the c axis of crystallites in the textured HTSC has been proposed. © 2015, Pleiades Publishing, Ltd.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G.
Заглавие : Modification of magnetic and superconducting properties of layered cuprates due to copper substitution for zinc and nickel
Место публикации : Fiz. Tverd. Tela: MEZHDUNARODNAYA KNIGA, 1995. - Vol. 37, Is. 12. - P3645-3654. - ISSN 0367-3294
Примечания : Cited References: 28
Предметные рубрики: ELECTRONIC-STRUCTURE
LA2CUO4
LA2-XSRXCUO4
EXCITATIONS
DENSITY
PLANE
NI
WOS
Найти похожие

18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Val'kov V. V., Dzebisashvili D. M., Korovushkin M. M., Barabanov A. F.
Заглавие : Stability of the superconducting dx2-y2 phase in high-Tc superconductors with respect to the intersite coulomb repulsion of holes at oxygen
Коллективы : Russian Foundation for Basic Research [16-02-00073, 16-02-00304]; Dynasty Foundation; Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools [SP-1361.2015.1]
Место публикации : JETP Letters. - 2016. - Vol. 103, Is. 6. - P.385-389. - ISSN 0021-3640, DOI 10.1134/S0021364016060114. - ISSN 1090-6487(eISSN)
Примечания : Cited References:28. - This work was supported by the Russian Foundation for Basic Research, project nos. 16-02-00073 and 16-02-00304. The work of D.D.M. and M.M.K. was supported by the Dynasty Foundation and the work of M.M.K. was also supported by the Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools (project no. SP-1361.2015.1).
Предметные рубрики: Hubbard-model
Spin polaron
Density
Аннотация: It has been shown that, because of the two-orbital character of the subsystem of holes located at oxygen sites and the spatial separation of this subsystem from that of spins at copper ions, the superconducting phase in high-Tc superconductors is stable with respect to the strong Coulomb repulsion of holes located at nearestneighbor oxygen sites if the order parameter has the dx2−y2 symmetry. This effect is due to the symmetry characteristics of the Coulomb potential, owing to which the equation determining the Cooper pairing in the dx2−y2 channel does not include this potential.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Avramov P. V., Kuzubov A. A., Fedorov D. G., Irle S., Morokuma K.
Заглавие : Strong Electron Correlations Determine Energetic Stability and Electronic Properties of Er-Doped Goldberg-Type Silicon Quantum Dots
Место публикации : J. Phys. Chem. C. - 2009. - Vol. 113, Is. 36. - P.15964-15968. - SEP 10. - ISSN 1932-7447, DOI 10.1021/jp904996e
Примечания : Cited Reference Count: 43. - Гранты: This work was supported by a CREST (Core Research for Evolutional Science and Technology) grant in the Area of High Performance Computing for Multiscale and Multiphysics Phenomena from the Japan Science and Tcchnology Agency (JST) and a collaborative RFBR-JSPS Grant 0902-92107-Phi. One of the authors (S.I.) also acknowledges support by the Program for Improvement of Research Environment for Young Researchers from Special Coordination Funds for Promoting Science and Technology (SCF) commissioned by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.Финансирующая организация: Japan Science and Tcchnology Agency (JST); RFBR-JSPS Grant; Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan
Предметные рубрики: IMPLANTED POROUS SILICON
AUGMENTED-WAVE METHOD
MU M LUMINESCENCE
SI NANOCRYSTALS
THIN-FILMS
BASIS-SET
ERBIUM
PHOTOLUMINESCENCE
DENSITY
PSEUDOPOTENTIALS
Ключевые слова (''Своб.индексиров.''): ab initio--atomic structure--density functionals--empirical pseudo-potential--endohedrals--energetic stability--er-doped--erbium complexes--erbium ion--experimental data--hartree-fock--many body perturbation theory--mass centers--perturbation approach--plane wave--pseudopotentials--quantum dot--silicon quantum dots--strong binding--strong electron correlations--theoretical result--crystal atomic structure--electron correlations--electron density measurement--electronic properties--electronic structure--erbium--perturbation techniques--structural optimization--semiconductor quantum dots
Аннотация: Atomic and electronic structures of Goldberg-type silicon quantum dots and their endohedral erbium complexes were studied using ab initio and plane wave pseudopotential density functional and Moller-Plesset many-body perturbation theories. During atomic structure optimizations, the erbium ions occupy mass centers inside the central hollows of quantum dots of different symmetries. It was found that strong electron correlations within the Er 4f shell taken into account by empirical pseudopotential and post-Hartree-Fock perturbation approaches are responsible for strong binding of Er ions to quantum dots. We elucidate the effects of symmetry and discuss theoretical results in comparison to available experimental data,
WOS,
Scopus,
eLibrary,
http://pubs.acs.org/doi/abs/10.1021/jp904996e.
Найти похожие

20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Frolov G. I., Zhigalov V. S., Polskii A. I., Pozdnyakov V. G.
Заглавие : Study of electroconductivity in cobalt nanocrystalline films
Место публикации : Fiz. Tverd. Tela: MEZHDUNARODNAYA KNIGA, 1996. - Vol. 38, Is. 4. - P1208-1213. - ISSN 0367-3294
Примечания : Cited References: 13
Предметные рубрики: METAL-FILMS
RESISTIVITY
CONDUCTION
ELECTRONS
DENSITY
WOS
Найти похожие