Труды сотрудников института физики

/ M. M. Korshunov [et al.] // Phys. Rev. B. - 2007. - Vol. 75, Is. 9. - Ст. 94511, DOI 10.1103/PhysRevB.75.094511. - Cited References: 47 . - ISSN 1098-0121РУБ Physics, Condensed Matter

Аннотация: Based on the ab initio band structure for NaxCoO2, we derive the single-electron energies and the effective tight-binding description for the t(2g) bands using projection procedure. Due to the presence of the next-nearest-neighbor hoppings, a local minimum in the electronic dispersion close to the Gamma point of the first Brillouin zone forms. Correspondingly, in addition to a large Fermi surface, an electron pocket close to the Gamma point emerges at high doping concentrations. The latter yields a scattering channel, resulting in a peak structure of the itinerant magnetic susceptibility at small momenta. This indicates dominant itinerant in-plane ferromagnetic fluctuations above a certain critical concentration x(m), in agreement with neutron scattering data. Below x(m), the magnetic susceptibility shows a tendency toward the antiferromagnetic fluctuations. We further analyze the many-body effects on the electronic and magnetic excitations using various approximations applicable for different U/t ratios.

WOS,
Scopus,
Для получение полного текста обратитесь в библиотеку

Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
Max Planck Inst Phys Komplexer Syst, D-01187 Dresden, Germany
Tech Univ Braunschweig, Inst Math & Theoret Phys, D-38106 Braunschweig, Germany
Russian Acad Sci, Ural Div, Inst Met Phys, Yetaterinburg 620041, Russia
ИФ СО РАН
L. V. Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences, 660036 Krasnoyarsk, Russian Federation
Max-Planck-Institut fur Physik Komplexer Systeme, D-01187 Dresden, Germany
Institute fur Mathematische und Theoretische Physik, TU Braunschweig, 38106 Braunschweig, Germany
Institute of Metal Physics, Russian Academy of Sciences, Ural Division, 620041 Yekaterinburg GSP-170, Russian Federation

Доп.точки доступа:
Korshunov, M. M.; Коршунов, Максим Михайлович; Eremin, I.; Shorikov, A.; Anisimov, V. I.; Renner, M.; Brenig, W.

/ M. M. Korshunov [et al.] // JETP Letters. - 2007. - Vol. 84, Is. 12. - P. 650-655, DOI 10.1134/S0021364006240040. - Cited References: 31 . - ISSN 0021-3640РУБ Physics, Multidisciplinary

Аннотация: Starting from the ab initio band structure for Na (x) CoO2, we derive the single-electron energies and the effective tight-binding description for the t (2g) bands using a projection procedure. We find that, due to the presence of the next-nearest-neighbor hoppings, a local minimum in the electronic dispersion close to the Gamma point of the first Brillouin zone forms. Therefore, in addition to a large Fermi surface, an electron pocket close to the Gamma point emerges at high doping concentrations. The latter yields a new scattering channel resulting in the peak structure of the itinerant magnetic susceptibility at low momenta. This indicates an itinerant in-plane ferromagnetic state above a certain critical concentration x(m) , which is in agreement with neutron scattering data. Below x(m) , the magnetic susceptibility shows a tendency towards antiferromagnetic fluctuations. We estimate the value of 0.56 < x(m) < 0.68 within the rigid band model and within the Hubbard model with infinite on-site Coulomb repulsion consistent with the experimental phase diagram.

WOS,
Scopus,
Для получение полного текста обратитесь в библиотеку

Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Div, Krasnoyarsk 660036, Russia
Max Planck Inst Phys Komplexer Syst, D-01187 Dresden, Germany
Tech Univ Carolo Wilhelmina Braunschweig, Inst Math Phys & Theoret Phys, D-38106 Braunschweig, Germany
Russian Acad Sci, Inst Met Phys, Ural Div, Ekaterinburg 620041, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Max-Planck-Institut fur Physik Komplexer Systems, D-01187 Dresden, Germany
Institut fur Mathematische Physik and Theoretische Physik, TU Braunschweig, 38106 Braunschweig, Germany
Institute of Metal Physics, Ural Division, Russian Academy of Sciences, Yekaterinburg, GSP-170, 620041, Russian Federation

Доп.точки доступа:
Korshunov, M. M.; Коршунов, Максим Михайлович; Eremin, I.; Shorikov, A.; Anisimov, V. I.

/ M. M. Korshunov [et al.] // J. Exp. Theor. Phys. - 2004. - Vol. 99, Is. 3. - P. 559-565, DOI 10.1134/1.1809685. - Cited References: 48 . - ISSN 1063-7761РУБ Physics, Multidisciplinary

Аннотация: We consider the problem of determining the parameters for high-T-c superconducting copper oxides. Alternative approaches, the ab initio LDA and LDA + U calculations and the generalized tight-binding (GTB) method for strongly correlated electron systems, are used to calculate hopping and exchange parameters of the effective singlet-triplet model for the CuO2 layer. The resulting parameters are in remarkably good agreement with each other and with parameters extracted from experiment. This set of parameters is proposed for proper quantitative description of the physics of hole-doped high-T-c cuprates in the framework of effective models. (C) 2004 MAIK "Nauka / Interperiodica".

WOS,
Scopus,
Для получение полного текста обратитесь в библиотеку

Держатели документа:
Russian Acad Sci, Kirensky Inst Phys, Siberian Div, Krasnoyarsk 660036, Russia
Russian Acad Sci, Inst Met Phys, Ural Div, Ekaterinburg 620219, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Institute of Metal Physics, Ural Division, Russian Academy of Sciences, Ekaterinburg, 620219, Russian Federation

Доп.точки доступа:
Korshunov, M. M.; Коршунов, Максим Михайлович; Gavrichkov, V. A.; Гавричков, Владимир Александрович; Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Pchelkina, Z. V.; Nekrasov, I. A.; Korotin, M. A.; Anisimov, V. I.