Z. V. Pchelkina

Electronic structure of prototype AFe2As2 and ReOFeAs high-temperature superconductors: A comparison

We have performed ab initio LDA calculations of the electronic structure of newly discovered prototype high-temperature superconductors AFe2As2 (A = Ba, Sr) and compared it with the previously calculated electronic spectra of ReOFeAs (Re = La, Ce, Pr, Nd, Sm). In all cases, we obtain almost identical densities of states in a rather wide energy interval (up to 1 eV) around the Fermi level. Energy dispersions are also very similar and almost two dimensional in this energy interval, leading to the same basic (minimal) model of the electronic spectra, determined mainly by Fe d orbitals of the FeAs layers. The other constituents, such as A ions or rare-earth Re (or oxygen states) are more or less irrelevant for superconductivity. LDA Fermi surfaces for AFe2As2 are also very similar to that of ReOFeAs. This makes the more simple AFe2As2 a generic system to study the high-temperature superconductivity in FeAs-layered compounds.

Electronic structure of new LiFeAs high-Tc superconductor

We present results of ab initio LDA calculations of electronic structure of “next generation” layered iron-pnictide high-Tc superconductor LiFeAs (Tc = 18 K). Obtained electronic structure of LiFeAs very similar to recently studied ReOFeAs (Re = La, Ce, Pr, Nd, Sm) and AFe2As2 (A = Ba, Sr) compounds. Namely close to the Fermi level its electronic properties are also determined mainly by Fe 3d-orbilats of FeAs4 two-dimensional layers. Band dispersions of LiFeAs are very similar to the LaOFeAs and BaFe2As2 systems as well as the shape of the Fe-3d density of states and Fermi surface.

Hybrid LDA and generalized tight-binding method for electronic structure calculations of strongly correlated electron systems

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 model. In strong correlation regime the electronic structure within multiband Hubbard model is calculated by the Generalized Tight-Binding (GTB) method, that combines the exact diagonalization of the model Hamiltonian for a small cluster (unit cell) with perturbation treatment of the intercluster hopping and interactions. For undoped La

High-temperature superconductivity in transition metal oxypnictides: A rare-earth puzzle?

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Magnetic-field control of the electric polarization in BiMnO3

CuO

Orbital-selective pressure-driven metal to insulator transition in FeO from dynamical mean-field theory

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Electronic structure of Bi M O 3 multiferroics and related oxides

and Nd

Orbital ordering and magnetic interactions in BiMnO3

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Crystal-field splitting for low symmetry systems in ab initio calculations

CuO

Evidence for strong electronic correlations in the spectra of Sr2RuO4

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