Electronic Structure of New AFFeAs Prototype of Iron Arsenide Superconductors (2008)
Nekrasov, I. A., Pchelkina, Z. V., Sadovskii, M. V.
This work is provoked by recent discovery of new class prototype systems AFFeAs (A=Sr,Ca) of novel layered ironpnictide High-Tc superconductors (Tc=36K). Here we report ab initio LDA results for...
Lukoyanov, A. V., Medvedev, M. V., Nekrasov, I. A.
In the framework of the LSDA+U method electronic structure and magnetic properties of the intermetallic compound Gd2Fe17 for both rhombohedral and hexagonal phases have been calculated. On top of...
Electronic Structure of New LiFeAs High-Tc Superconductor (2008)
Nekrasov, I. A., Pchelkina, Z. V., Sadovskii, M. V.
We present results of it ab initio LDA calculations of electronic structure of "next generation" layered ironpnictide High-Tc superconductor LiFeAs (Tc=18K). Obtained electronic structure of LiFeAs...
Nekrasov, I. A., Pchelkina, Z. V., Sadovskii, M. V.
We have performed ab initio LDA calculations of electronic structure of newly discovered prototype high-temperature superconductors AFe_2As_2 (A=Ba,Sr) and compared it with previously calculated...
Kokorina, E. E., Kuchinskii, E. Z., Nekrasov, I. A., Pchelkina, Z. V., Sadovskii, M. V., Sekiyama, A., ...
Material specific electronic band structure of the electron-doped high-Tc cuprate Nd(1.85)Ce(0.15)CuO(4) (NCCO) is calculated within the pseudo gap regime, using the recently developed generalized...
High Temperature Superconductivity in Transition Metal Oxypnictides: a Rare-Earth Puzzle? (2008)
Nekrasov, I. A., Pchelkina, Z. V., Sadovskii, M. V.
We have performed an extensive ab initio LDA and LSDA+U calculations of electronic structure of newly discovered high-temperature superconducting series ReO(1-x)F(x)FeAs (Re=La,Ce, Pr, Nd, Sm and...
Optical Sum Rule in Strongly Correlated Systems (2008)
Kuchinskii, E. Z., Kuleeva, N. A., Nekrasov, I. A., Sadovskii, M. V.
We discuss the problem of a possible "violation" of the optical sum rule in the normal (non superconducting) state of strongly correlated electronic systems, using our recently proposed DMFT+Sigma...
Uruma, M., Sekiyama, A., Fujiwara, H., Yano, M., Fujita, H., Imada, S., ...
We report on experimental data of the three-dimensional bulk Fermi surfaces of the layered strongly correlated Ca1.5Sr0.5RuO4 system. The measurements have been performed by means of hn-depndent...
Nekrasov, I. A., Kokorina, E. E., Kuchinskii, E. Z., Pchelkina, Z. V., Sadovskii, M. V.
Pseudogap regime for the prototype high-Tc compounds hole doped Bi2Sr2CaCu2O8-x (Bi2212) and electron doped Nd2-xCexCuO4 (NCCO) is described by means of novel generalized LDA+DMFT+Sk approach. Here...
Kuchinskii, E. Z., Nekrasov, I. A., Sadovskii, M. V.
Density of states, dynamic (optical) conductivity and phase diagram of strongly correlated and strongly disordered paramagnetic Anderson-Hubbard model are analyzed within the generalized dynamical...
Korshunov, M. M., Gavrichkov, V. A., Ovchinnikov, S. G., Nekrasov, I. A., Kokorina, E. E., Pchelkina, Z. V.
In the present work we report the band structure calculations for the high temperature superconductor Nd$_{2-x}$Ce$_x$CuO$_4$ in the regime of strong electronic correlations within an LDA+GTB method,...
Electronic Properties of the Semiconductor RuIn$_3$ (2007)
Bogdanov, D., Winzer, K., Nekrasov, I. A., Pruschke, T.
Temperature dependent measurements of the resistivity on RuIn$_3$ single crystals show a semiconducting behaviour, in contrast to previously published results. In the high temperature range the...
Korshunov, M.M., Gavrichkov, V.A., Ovchinnikov, S.G., Nekrasov, I.A., Kokorina, E.E., Pchelkina, Z.V.
Kinks in the dispersion of strongly correlated electrons (2006)
Byczuk, K., Kollar, M., Held, K., Nekrasov, I. A., Pruschke, Th., ...
The properties of condensed matter are determined by single-particle and collective excitations and their interactions. These quantum-mechanical excitations are characterized by an energy E and a...
Kuchinskii, E. Z., Nekrasov, I. A., Sadovskii, M. V.
Optical conductivity of the weakly doped two-dimensional repulsive Hubbard model on the square lattice with nearest and next nearest hoppings is calculated within the generalized dynamical-mean field...
Pseudogap behaviour in Bi2212: Results of Generalized DMFT Approach (2006)
Kuchinskii, E. Z., Nekrasov, I. A., Pchelkina, Z. V., Sadovskii, M. V.
To describe pseudogap regime in Bi2212 we employ novel generalized ab initio LDA+DMFT+Sigma_k hybrid scheme. This scheme is based on the strategy of one of the most powerfull computational tool for...
Evidence for strong electronic correlations in the spectra of Sr$_2$RuO$_4$ (2006)
Pchelkina, Z. V., Nekrasov, I. A., Pruschke, Th., Sekiyama, A., Suga, S., Anisimov, V. I., ...
The importance of electronic correlation effects in the layered perovskite Sr$_2$RuO$_4$ is evidenced. To this end we use state-of-the-art LDA+DMFT (Local Density Approximation + Dynamical Mean-Field...
Knyazev, Yu. V., Lukoyanov, A. V., Kuz'min, Yu. I., Kuchin, A. G., Nekrasov, I. A.
In this paper we report comprehensive experimental and theoretical investigation of magnetic and electronic properties of the intermetallic compounds Pr2Fe17 and Gd2Fe17. For the first time...
Momentum-resolved spectral functions of SrVO3 calculated by LDA+DMFT (2006)
Nekrasov, I. A., Held, K., Keller, G., Kondakov, D. E., Pruschke, T., Kollar, M., ...
LDA+DMFT, the merger of density functional theory in the local density approximation and dynamical mean-field theory, has been mostly employed to calculate k-integrated spectra accessible by...
Realistic investigations of correlated electron systems with LDA plus DMFT (2006)
Held, K., Nekrasov, I. A., Keller, G., Eyert, V., Blumer, N., McMahan, A. K., ...
Conventional band structure calculations in the local density approximation (LDA) [1-3] are highly successful for many materials, but miss important aspects of the physics and energetics of strongly...
Pseudogaps: Introducing the Length Scale into DMFT (2005)
Kuchinskii, E. Z., Nekrasov, I. A., Sadovskii, M. V.
Pseudogap physics in strongly correlated systems is essentially scale dependent. We generalize the dynamical mean field theory (DMFT) by including into the DMFT equations dependence on correlation...
Pseudogaps in Strongly Correlated Metals: A generalized dynamical mean-field theory approach (2005)
Sadovskii, M. V., Nekrasov, I. A., Kuchinskii, E. Z., Pruschke, Th., Anisimov, V. I.
We generalize the dynamical-mean field (DMFT) approximation by including into the DMFT equations some length scale via a momentum dependent ``external'' self-energy S(k). This external self-energy...
Momentum-resolved spectral functions of SrVO$_3$ calculated by LDA+DMFT (2005)
Nekrasov, I. A., Held, K., Keller, G., Kondakov, D. E., Pruschke, Th., Kollar, M., ...
LDA+DMFT, the merger of density functional theory in the local density approximation and dynamical mean-field theory, has been mostly employed to calculate k-integrated spectra accessible by...
Kuchinskii, E. Z., Nekrasov, I. A., Sadovskii, M. V.
We generalize the dynamical - mean field theory (DMFT) by including into the DMFT equations dependence on correlation length of pseudogap fluctuations via additional (momentum dependent) self -...
Gavrichkov, V. A., Korshunov, M. M., Ovchinnikov, S. G., Nekrasov, I. A., Pchelkina, Z. V., Anisimov, V. I.
A novel hybrid scheme is proposed. The {\it ab initio} LDA calculation is used to construct the Wannier functions and obtain single electron and Coulomb parameters of the multiband Hubbard-type...
Anisimov, V. I., Korotin, M. A., Nekrasov, I. A., Mylnikova, A. S., Lukoyanov, A. V., ...
We have investigated the role of transition metal impurities and oxygen vacancies in the formation of ferromagnetism in Co-doped TiO2 using LSDA+U approach which takes into account strong on-cite...
Pseudogaps in Strongly Correlated Metals (2005)
Sadovskii, M. V., Nekrasov, I. A., Kuchinskii, E. Z., Pruschke, Th., Anisimov, V. I.
We generalize the dynamical-mean field (DMFT) approximation by including into the DMFT equations some length scale via a (momentum dependent) ``external'' self-energy \Sigma_k. This external...
Comparative study of correlation effects in CaVO3 and SrVO3 (2005)
Nekrasov, I. A., Keller, G., Kondakov, D. E., Kozhevnikov, A. V., Pruschke, Th., Held, K., ...
We present parameter-free LDA+DMFT (local density approximation + dynamical mean field theory) results for the many-body spectra of cubic SrVO3 and orthorhombic CaVO3. Both systems are found to be...
Dynamical mean-field theory and its applications to real materials (2005)
Vollhardt, D., Held, K., Keller, G., Bulla, R., Pruschke, T., Nekrasov, I. A., ...
Comparative study of correlation effects in CaVO3 and SrVO3 (2005)
Nekrasov, I. A., Keller, G., Kondakov, D. E., Kozhevnikov, A. V., Pruschke, T., Held, K., ...
Dynamical Mean-Field Theory and Its Applications to Real Materials (2004)
Vollhardt, D., Held, K., Keller, G., Bulla, R., Pruschke, Th., Nekrasov, I. A., ...
Dynamical mean-field theory (DMFT) is a non-perturbative technique for the investigation of correlated electron systems. Its combination with the local density approximation (LDA) has recently led to...
Full orbital calculation scheme for materials with strongly correlated electrons (2004)
Anisimov, V. I., Kondakov, D. E., Kozhevnikov, A. V., Nekrasov, I. A., Pchelkina, Z. V., Allen, J. W., ...
We propose a computational scheme for the ab initio calculation of Wannier functions (WFs) for correlated electronic materials. The full-orbital Hamiltonian H is projected into the WF subspace...
Korshunov, M. M., Gavrichkov, V. A., Ovchinnikov, S. G., Pchelkina, Z. V., Nekrasov, I. A., Korotin, M. A., ...
The present paper covers the problem of parameters determination for High-$T_c$ superconductive copper oxides. Different approaches, {\it ab initio} LDA and LDA+U calculations and Generalized...
Mutual Experimental and Theoretical Validation of Bulk Photoemission Spectra of Sr1-xCaxVO3 (2004)
Sekiyama, A., Fujiwara, H., Imada, S., Suga, S., Eisaki, H., Uchida, S. I., ...
Influence of Co$^{3+}$ spin-state on optical properties of LaCoO$_3$ and HoCoO$_3$ (2003)
Nomerovannaya, L. V., Makhnev, A. A., Streltsov, S. V., Nekrasov, I. A., Korotin, M. A., Shiryaev, S. V., ...
Optical properties of the isoelectronic compounds LaCoO$_3$ and HoCoO$_3$ has been experimentally and theoretically investigated. We've measured the real $\epsilon_1(\omega)$ and imaginary...
Mutual Experimental and Theoretical Validation of Bulk Photoemission Spectra of Sr1-xCaxVO3 (2003)
Sekiyama, A., Fujiwara, H., Imada, S., Suga, S., Eisaki, H., Uchida, S. I., ...
We report high-resolution high-energy photoemission spectra together with parameter-free LDA+DMFT (local density approximation + dynamical mean-field theory) results for Sr1-xCaxVO3, a prototype 3d1...
Nekrasov, I. A., Streltsov, S. V., Korotin, M. A., Anisimov, V. I.
We present first principles LDA+U calculations of electronic structure and magnetic state for LaCoO3 and HoCoO3. Low Spin to Intermediate Spin state transition was found in our calculations using...
Orbital state and magnetic properties of LiV2O4 (2003)
Nekrasov, I. A., Pchelkina, Z. V., Keller, G., Pruschke, T., Held, K., Krimmel, A., ...
LDA+DMFT investigations of transition metal oxides and f-electron materials (2003)
Held, K., Anisimov, V. I., Eyert, V., Keller, G., McMahan, A. K., Nekrasov, I. A., ...
Realistic investigations of correlated electron systems with LDA+DMFT (2003)
Held, K., Nekrasov, I. A., Keller, G., Eyert, V., Blümer, N., McMahan, A. K., ...
Explanation of the similarity of the experimental photoemission spectra of SrVO3 and CaVO3 (2002)
Nekrasov, I. A., Keller, G., Kondakov, D. E., Kozhevnikov, A. V., Pruschke, Th., Held, K., ...
We present parameter-free LDA+DMFT results for the many-particle density of states of cubic SrVO3 and orthorhombic CaVO3. Both systems are found to be strongly correlated metals, but em not on the...
Orbital state and magnetic properties of LiV_2 O_4 (2002)
Nekrasov, I. A., Pchelkina, Z. V., Keller, G., Pruschke, Th., Held, K., Krimmel, A., ...
LiV_2 O_4 is one of the most puzzling compounds among transition metal oxides because of its heavy fermion like behavior at low temperatures. In this paper we present results for the orbital state...
First Principle Electronic Model for High-Temperature Superconductivity (2002)
Anisimov, V. I., Korotin, M. A., Nekrasov, I. A., Pchelkina, Z. V., Sorella, S.
Using the structural data of the La2CuO4 compound both in the low temperature tetragonal phase and in the isotropic phase we have derived an effective t-J model with hoppings t and superexchange...
The LDA+DMFT Approach to Materials with Strong Electronic Correlations (2001)
Held, K., Nekrasov, I. A., Keller, G., Eyert, V., Blümer, N., McMahan, A. K., ...
LDA+DMFT is a novel computational technique for ab initio investigations of real materials with strongly correlated electrons, such as transition metals and their oxides. It combines the strength of...
Anisimov, V. I., Nekrasov, I. A., Kondakov, D. E., Rice, T. M., Sigrist, M.
The electronic structures of the metallic and insulating phases of the alloy series Ca(2-x)Sr(x)RuO4 (0
Zölfl, M. B., Nekrasov, I. A., Pruschke, Th., Anisimov, V. I., Keller, J.
We have calculated ground state properties and excitation spectra for Ce metal with the {\it ab initio} computational scheme combining local density approximation and dynamical mean-field theory...
Localization in ruthenates: magnetic and electronic properties of Ca(2-x)Sr(x)RuO(4) (2000)
Anisimov, V. I., Nekrasov, I. A., Kondakov, D. E., Rice, T. M., Sigrist, M.
The electronic structures of the metallic and insulating phases of Ca(2-x)Sr(x)RuO(4) (0
Held, K., Nekrasov, I. A., Blümer, N., Anisimov, V. I., Vollhardt, D.
The LDA+DMFT approach merges conventional band structure theory in the local density approximation (LDA) with a state-of-the-art many-body technique, the dynamical mean-field theory (DMFT). This new...
Nekrasov, I. A., Korotin, M. A., Anisimov, V. I.
Coulomb interaction between electrons on p-orbitals of oxygen atom in strongly correlated compounds is not negligible, since its value (U_p) has comparable order of magnitude with the value of...
Nekrasov, I. A., Held, K., Blümer, N., Poteryaev, A. I., Anisimov, V. I., Vollhardt, D.
The spectral properties of La$_{1-x}$Sr$_{x}$TiO$_{3}$, a doped Mott insulator with strong Coulomb correlations, are calculated with the ab initio computational scheme LDA+DMFT(QMC). It starts from...
LDA+DMFT study for $La_{1-x}Sr_{x}TiO_{3}$ (1999)
Zoelfl, M. B., Pruschke, Th., Keller, J., Poteryaev, A. I., Nekrasov, I. A., Anisimov, V. I.
The dynamical mean-field theory together with the non-crossing approximation is used to set up a novel scheme to study the electronic structure of strongly correlated electron systems. The...
Alekseev,V. R., Nekrasov,I. A., Nikitina,N. M., Nevskii,S. D., Rudavin,V. V.
In the book, the authors examine the basic tendencies in the occurrence of ice bodies within the confines of individual large regions, the formation and regime of ice bodies, their role in river...