Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
в найденном
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>S=SPIN<.>)
Общее количество найденных документов : 21
Показаны документы с 1 по 10
 1-10    11-21   21-21 
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zobov V. E., Shauro V. P.
Заглавие : Selective control of the states of multilevel quantum systems using nonselective rotation operators
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2009. - Vol. 108, Is. 1. - P5-17. - ISSN 1063-7761, DOI 10.1134/S1063776109010026
Примечания : Cited References: 20
Предметные рубрики: FOURIER-TRANSFORM
SPIN
Ключевые слова (''Своб.индексиров.''): quantum electronics--quantum optics--quadrupole nucleus--quantum systems--radio frequencies--rf fields--rf pulse--selective controls--selective pulse--rotation
Аннотация: We have calculated the sequences of nonselective rotation operators separated by intervals of free evolution that perform selective rotations between adjacent levels in systems with three, four, five, and six nonequidistant levels. We have numerically simulated the realization of the calculated sequences for quadrupole nuclei with corresponding spins controlled by intense nonselective radio-frequency (RF) pulses and investigated the dependences of the realization error on the parameters of external and internal interactions. To reduce the error when the RF field is not strong enough, we have found composite nonselective RF pulses consisting of five simple ones. We show that the error of the composite selective rotation operator can be reduced signifi- cantly in comparison to the error of a simple single selective pulse.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Val'kov V. V., Mitskan V. A., Petrakovskii G. A.
Заглавие : The magnetoelastic mechanism of singlet phase formation in a two-dimensional quantum antiferromagnet
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2006. - Vol. 102, Is. 2. - P234-247. - ISSN 1063-7761, DOI 10.1134/S106377610602004X
Примечания : Cited References: 18
Предметные рубрики: GROUND-STATE
SPIN
TRANSITION
CUGEO3
MODEL
Ключевые слова (''Своб.индексиров.''): crystal lattices--elasticity--mathematical models--oscillations--phase diagrams--phase transitions--quantum theory--two dimensional--atomic representation--magnetoelastic mechanism--quantum antiferromagnets--singlet phase formation--antiferromagnetic materials
Аннотация: A model describing the second-order phase transition with respect to the magnetoelastic coupling parameter from the anti ferromagnetic (AFM) to the singlet state in a two-dimensional quantum magnet on a square lattice is proposed. The spectrum of elementary excitations in the singlet and AFM phases is calculated using an atomic representation, and the evolution of transverse and longitudinal branches of this spectrum is studied in the vicinity of the transition point. It is established that the AFM to singlet phase transition is related to softening of the longitudinal branch of oscillations. In the singlet phase, the gap plays the role of a parameter characterizing the distance to the phase transition point. It is shown that the spectrum of transverse oscillations in the AFM phase corresponds to the Goldstone boson. Based on an analysis of the stability of the spectrum of elementary excitations, a phase diagram is constructed that determines the regions of the existence of phases with plaquette-deformed lattices.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Val'kov V. V., Val'kova T. A., Mitskan V. A.
Заглавие : Gapless chiral superconducting (d + id)-wave phase in strongly correlated layered material with a triangular lattice
Коллективы : Russian Foundation for Basic ResearchRussian Foundation for Basic Research (RFBR) [19-02-00348, 18-42240014]; Krasnoyarsk Kray Science Foundation [18-42-240014]; Administration of the Krasnoyarsk Kray
Место публикации : J. Exp. Theor. Phys. - 2020. - Vol. 130, Is. 2. - P.235-246. - ISSN 1063-7761, DOI 10.1134/S1063776120010197. - ISSN 1090-6509(eISSN)
Примечания : Cited References: 44. - This study was supported by the Russian Foundation for Basic Research (project nos. 19-02-00348 and 18-42240014), the Administration of the Krasnoyarsk Kray, the Krasnoyarsk Kray Science Foundation within research project "Single-orbital Effective Model of Ensemble of Spin-Polaron Quasiparticles in the Problem of Description of the Intermediate State and Pseudogap Behavior of Cuprate Superconductors" (project no. 18-42-240014).
Предметные рубрики: TRANSITIONS
SPIN
Аннотация: It is shown that interlayer electron tunneling in the quasi-two-dimensional ensemble of Hubbard fermions leads to the realization of the gapless superconducting phase with the chiral (d + id)-wave order parameter symmetry, not for a single value of sodium ion concentration, but in a wide range of concentrations. Precisely this situation corresponds to experimental data on the layered sodium cobaltite intercalated by water (NaxCoO2 · yH2O). Intra-atomic electron repulsion that determines the strong electron correlation regime leads to the representation of Hubbard fermions, the interaction of which ensures Cooper instability. Intersite intralayer interactions between fermions considerably affect the positions of nodal points of the chiral order parameter and change the critical concentration at which a topological transition occurs in the 2D system of Hubbard fermions.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Dudnikov V. A., Fedorov A. S., Orlov Yu. S., Solovyov L. A., Vereshchagin S. N., Gavrilkin, S. Yu, Tsvetkov, A. Yu, Gorev M. V., Novikov, S., V, Ovchinnikov S. G.
Заглавие : Thermoelectric properties of the SmCoO3 and NdCoO3 cobalt oxides
Коллективы : Russian Science FoundationRussian Science Foundation (RSF) [16-13-00060]
Место публикации : Ceram. Int. - 2020. - Vol. 46, Is. 11. - P.17987-17991. - ISSN 0272-8842, DOI 10.1016/j.ceramint.2020.04.113. - ISSN 1873-3956(eISSN)
Примечания : Cited References: 41. - This study was supported by the Russian Science Foundation, project no. 16-13-00060.
Предметные рубрики: MAGNETIC-PROPERTIES
SPIN
CONDUCTIVITY
TRANSITIONS
LACOO3
SITE
Аннотация: The thermoelectric properties of the NdCoO3 and SmCoO3 rare-earth cobalt oxides with a perovskite structure have been investigated in a wide temperature range. It is shown that, in the low-temperature region, the thermal conductivity of the compounds has a sharp maximum and the electrical conductivity of the samples increases with temperature, whereas the Seebeck coefficient behaves nonmonotonically with increasing temperature. The SmCoO3 oxide is characterized by the positive thermopower over the entire investigated range with a sharp growth in the low-temperature region, attaining the maximum value (S ≈ 1000 μV/K) near room temperature, and a further decrease. It has been established that, in the NdCoO3 oxide, the Seebeck coefficient changes its sign, which was rarely observed in the La-based compounds and is atypical of the undoped rare-earth cobalt oxides. The thermopower maximum obtained at a temperature of 450 K is 400 μV/K. The regions of the fastest growth of the thermoelectric power factor correspond to the anomalies caused by the spin transition of Со3+ ions and the dielectric–metal transition.
Смотреть статью,
Читать в сети ИФ,
Scopus,
WOS
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Orlov Yu. S., Dudnikov V. A., Gorev M. V., Vereshchagin S. N., Solov’ev L. A., Ovchinnikov S. G.
Заглавие : Thermal properties of rare earth cobalt oxides and of La1–xGdxCoO3 solid solutions
Место публикации : JETP Letters. - 2016. - Vol. 103, Is. 9. - P.607-612. - ISSN 00213640 (ISSN), DOI 10.1134/S0021364016090058
Примечания : Cited References: 21. - This work was supported by the Russian Foundation for Basic Research, project nos. 16-02-00507 and 16-02-00098, and by the Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools, project no. SP-1844.2016.1. The X-ray diffraction analysis of the crystal structure and the measurement of specific heat were supported by the Siberian Branch, Russian Academy of Sciences (project no. V.45.3.1).
Предметные рубрики: PROFILE REFINEMENT
SPIN
CRYSTALS
Аннотация: Powder X-ray diffraction data for the crystal structure, phase composition, and molar specific heat for La1‒xGdxCoO3 cobaltites in the temperature range of 300–1000 K have been analyzed. The behavior of the volume thermal expansion coefficient in cobaltites with isovalent doping in the temperature range of 100–1000 K is studied. It is found that the β(T) curve exhibits two peaks at some doping levels. The rate of the change in the occupation number for the high-spin state of cobalt ions is calculated for the compounds under study taking into account the spin–orbit interaction. With the Birch–Murnaghan equation of state, it is demonstrated that the low-temperature peak in the thermal expansion shifts with the growth of the pressure toward higher temperatures and at pressure P ∼ 7 GPa coincides with the second peak. The similarity in the behavior of the thermal expansion coefficient in the La1–xGdxCoO3 compounds with the isovalent substitution and the undoped LnCoO3 compound (Ln is a lanthanide) is considered. For the whole series of rare earth cobalt oxides, the nature of two specific features in the temperature dependence of the specific heat and thermal expansion is revealed and their relation to the occupation number for the high-spin state of cobalt ions and to the insulator–metal transition is established.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shorikov A., Korshunov M. M., Anisimov V. I.
Заглавие : Role of electronic correlations in the Fermi surface formation of Na (x) CoO2
Разночтения заглавия :авие SCOPUS: Role of electronic correlations in the Fermi surface formation of Na xCoO 2
Место публикации : JETP Letters. - 2011. - Vol. 93, Is. 2. - P.80-85. - ISSN 0021-3640, DOI 10.1134/S0021364011020123
Примечания : Cited References: 36. - The authors thank I. Eremin, M. Laad, and S. G. Ovchinnikov for useful discussions. A. S. and V. I. A. acknowledge the support of the Russian Foundation for Basic Research (project nos. 10-02-00046-a, 09-02-00431-a, and 10-02-00546-a), the Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools (project nos. NSh-1941.2008.2 and MK-3758.2010.2), the Presidium of the Russian Academy of Science (programs "Quantum Microphysics of Condensed Matter" N7 and "Strongly Compressed Materials"), and the Russian Federal Agency for Science and Innovations (project no. 02.740.11.0217). M. M. K. acknowledges the support of INTAS (YS Grant no. 05-109-4891); the Russian Foundation for Basic Research (project nos. 09-02-00127, 06-02-16100, and 06-02-90537-BNTS); the Siberian Branch, Russian Academy of Sciences (integration program no. 40); the Presidium of the Russian Academy of Sciences (program no. 5.7); the Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools (project no. MK-1683.2010.2); and the Ministry of Education and Science of the Russian Federation (project no. R891, federal program "Scientific and Pedagogical Personnel of Innovative Russia for 2009-2013").
Предметные рубрики: DENSITY-FUNCTIONAL CALCULATION
METALS
SPIN
Аннотация: Band structure of metallic sodium cobaltate Na (x) CoO2 (x = 0.33, 0.48, 0.61, 0.72) has been investigated by local density approximation + Hubbard U (LDA+U) method and within Gutzwiller approximation for the Co-t (2g) manifold. Correlation effects being taken into account results in suppression of the e' (g) hole pockets at the Fermi surface in agreement with recent angle-resolved photoemission spectroscopy (ARPES) experiments. In the Gutzwiller approximation the bilayer splitting is significantly reduced due to the correlation effects. The formation of high spin (HS) state in Co d-shell was shown to be very improbable.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shneyder E. I., Ovchinnikov S. G., Shnurenko A. V.
Заглавие : Contribution of the non-Heisenberg ring exchange to the magnetic mechanism of high-Tc superconductivity
Место публикации : JETP Letters. - 2012. - Vol. 95, Is. 4. - P.193-197. - ISSN 0021-3640, DOI 10.1134/S0021364012040078
Примечания : Cited References: 44. - This work was supported by the Council of the President of the Russian Federation for Support of Young Scientists and Leading Scientific Schools (project no. NSh-1044.2012.2), by the Russian Foundation for Basic Research (project no. 12-02-00040), by the Presidium of the Russian Academy of Sciences (program no. 20 "Quantum Mesoscopic and Disordered Systems"), jointly by the Siberian and Ural Branches of the Russian Academy of Sciences, by Siberian Federal University (project no. s/b S-11), and by the Ministry of Education and Science of the Russian Federation (state contract no. P891, federal program "Human Capital"). E.I.Sh. acknowledges the support of the Dynasty Foundation.
Предметные рубрики: BAND HUBBARD-MODEL
COPPER OXIDES
ELEMENTARY EXCITATIONS
SPIN
ELECTRON
STATE
T/U
Аннотация: The effect of non-Heisenberg four-spin ring exchange on the superconducting transition temperature in strongly correlated electron systems is studied. It is shown that the ring exchange can significantly suppress the contribution of the Heisenberg exchange to superconducting pairing.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Val'kov V. V., Mitskan V. A., Zlotnikov A. O., Shustin M. S., Aksenov S. V.
Заглавие : Occurrence of Topologically Nontrivial Phases, Cascade of Quantum Transitions, and Identification of Majorana Modes in Chiral Superconductors and Nanowires (Scientific Summary)
Коллективы : Russian Foundation for Basic ResearchRussian Foundation for Basic Research (RFBR) [16-02-00073, 18-32-00443, 19-02-00348]; Government of the Krasnoyarsk Territory; Krasnoyarsk Regional Fund of Science [18-42-243017, 18-42-243018, 18-42-240014]; Council of the President of the Russian Federation for State Support of Young Scientists and Leading Scientific SchoolsLeading Scientific Schools Program [MK-3722.2018.2, MK-3594.2018.2]
Место публикации : JETP Letters. - 2019. - Vol. 110, Is. 2. - P.140-153. - ISSN 0021-3640, DOI 10.1134/S002136401914011X. - ISSN 1090-6487(eISSN)
Примечания : Cited References: 88. - This work was supported by the Russian Foundation for Basic Research (project nos. 16-02-00073, 18-32-00443, 19-02-00348) and jointly by the Government of the Krasnoyarsk Territory, the Krasnoyarsk Regional Fund of Science (project no. 18-42-243017, "Manifestation of Coulomb Interactions and Effects of Bounded Geometry in the Properties of Topological Edge States of Nanostructures with Spin-Orbit Interaction"; project no. 18-42-243018, "Contact Phenomena and Magnetic Disorder in the Problem of the Formation and Detection of Topologically Protected Edge States in Semiconductor Nanostructures"; and project no. 18-42-240014, "Single-Orbit Effective Model of an Ensemble of Spin-Polaron Quasiparticles in the Problem of Describing the Intermediate State and Pseudogap Behavior of Cuprate Superconductors"). S.V. Aksenov and A. O. Zlotnikov acknowledge the support of the Council of the President of the Russian Federation for State Support of Young Scientists and Leading Scientific Schools (project nos. MK-3722.2018.2 and MK-3594.2018.2).
Предметные рубрики: HUBBARD FERMIONS
BOUND-STATE
SPIN
POLARIZATION
COEXISTENCE
Аннотация: The problems of occurrence and experimental identification of topologically nontrivial phases in condensed matter have been reviewed. The results of the study of the effect of strong intra- and interatomic Coulomb interaction on a quantum phase transition with change in the topological index in an ensemble of Hubbard fermions on a triangular lattice have been reported. Nontrivial topology of the phase of coexistence of d + id chiral superconductivity and 120° spin ordering in a system with the triangular lattice has been discussed and the formation of Majorana modes in such a phase has been demonstrated. A cascade of quantum transitions that occurs at the variation of the magnetic field or the electrochemical potential has been analyzed for an open nanowire with the Rashba spin-orbit coupling and the induced superconducting pairing potential. It has been shown that anomalies of magneto- and electrocaloric effects are manifested near such quantum transitions and can be used to experimentally test materials on the existence of topologically nontrivial phases in them. The switching of the spin-polarized current in the topological superconducting phase has been predicted for a semimetal/superconducting wire/semimetal structure in the weak nonequilibrium regime.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Martynov S. N.
Заглавие : Symmetrical conical incommensurate structures of a frustrated isotropic Heisenberg ferrimagnet
Место публикации : JETP Letters. - 2015. - Vol. 102, Is. 2. - P.100-104. - ISSN 0021, DOI 10.1134/S0021364015140076. - ISSN 10906487(eISSN)
Примечания : Cited References:16
Предметные рубрики: CLASSICAL-THEORY
SPIN
MULTIFERROICS
Аннотация: The conditions of the appearance of conical incommensurate structures have been studied analytically for a ferrimagnet with the geometrically frustrated exchange between spins in different magnetic positions (subsystems) and the competition between exchanges in one of the subsystems. The phase transition temperatures to the conical states have been determined. The types of phase transitions have been determined by the numerical minimization of the free energy and (temperature-exchange parameters) phase diagrams have been obtained.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volkov N. V., Tarasov A. S., Rautskii M. V., Lukyanenko A. V., Varnakov S. N., Ovchinnikov S. G.
Заглавие : Magnetic-field-driven electron transport in ferromagnetic/ insulator/ semiconductor hybrid structures
Коллективы : Euro-Asian Symposium "Trends in MAGnetism", "Trends in MAGnetism", Euro-Asian Symposium, Институт физики им. Л.В. Киренского Сибирского отделения РАН , Russian Foundation for Basic Research, Government of Krasnoyarsk Territory, Krasnoyarsk Region Science and Technology Support Fund [16-42-242036, 16-42-243046]; Russian Ministry of Education and Science [16.663.2014K]
Место публикации : J. Magn. Magn. Mater.: Elsevier Science, 2017. - Vol. 440: EURO-Asian Symposium on Trends in Magnetism (EASTMAG) (AUG 15-19, 2016, Siberian Fed Univ, Krasnoyarsk, RUSSIA). - P.140-143. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2016.12.092. - ISSN 1873-4766(eISSN)
Примечания : Cited References:27. - This study was supported by the Russian Foundation for Basic Research, Government of Krasnoyarsk Territory, Krasnoyarsk Region Science and Technology Support Fund, Project nos. 16-42-242036 and 16-42-243046, the Russian Ministry of Education and Science, state assignment no. 16.663.2014K.
Предметные рубрики: SPINTRONICS
BREAKDOWN
SILICON
SPIN
Ключевые слова (''Своб.индексиров.''): hybrid structures--magnetoresistance--magnetoimpedance--photovoltage
Аннотация: Extremely large magnetotransport phenomena were found in the simple devices fabricated on base of the Me/SiO2/p-Si hybrid structures (where Me are Mn and Fe). These effects include gigantic magnetoimpedance (MI), dc magnetoresistance (MR) and the lateral magneto-photo-voltaic effect (LMPE). The MI and MR values exceed 10(6)% in magnetic field about 0.2 T for Mn/SiO2/p-Si Schottky diode. LMPE observed in Fe/SiO2/p-Si lateral device reaches the value of 10(4)% in a field of 1 T. We believe that in case with the Schottky diode MR and MI effects are originate from magnetic field influence on impact ionization process by two different ways. First, the trajectory of the electron is deflected by a magnetic field, which suppresses acquisition of kinetic energy and therefore impact ionization. Second, the magnetic field gives rise to shift of the acceptor energy levels in silicon to a higher energy. As a result, the activation energy for impact ionization significantly increases and consequently threshold voltage rises. Moreover, the second mechanism (acceptor level energy shifting in magnetic field) can be responsible for giant LMPE.
Смотреть статью,
WOS,
Читать в сети ИФ
Найти похожие
 1-10    11-21   21-21 
 

Другие библиотеки

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