Related papers: Electronic State of Na_xCoO_2 Based on the Two Dim…
Kondo systems are usually described by the interaction of strong correlation induced local moment with the highly itinerant conduction electrons. Here, we study the role of electron correlations among conduction electrons in the electronic…
We used high resolution angle-resolved photoemission spectroscopy to reveal the Fermi surface and key transport parameters of the metallic state of the layered Colossal Magnetoresistive (CMR) oxide La1.2Sr1.8Mn2O7. With these parameters the…
Including on-site electronic interactions described by the multi-orbital Hubbard model we study the correlation effects in the electronic structure of bulk palladium. We use a combined density functional and dynamical mean field theory,…
Based on first-principles calculations, we explored the interplay between stacking effect and electron-electron correlation in the layered vdW material of bulk 1T-NbS2 with a 2D charge density wave (CDW) order. Without considering the…
Charge ordering in doped \cob planes near the commensurate fillings $x = {1/4}$ and 1/3 are considered for $Na_x CoO_2.yH_2O$ and suggested to be competitors to superconductivity, leading to the experimentally seen narrow superconducting…
We calculate the effective trigonal crystal field Delta which splits the t2g levels of effective models for NaxCoO2 as the local symmetry around a Co ion is reduced from Oh to D3d. To this end we solve numerically a CoO6 cluster containing…
Motivated by the recent discovery of charge density wave (CDW) order in the magnetic kagom\'e metal FeGe, we study the single-orbital $t$-$U$-$V_1$-$V_2$ model on the kagom\'e lattice, where $U$, $V_1$, and $V_2$ are the onsite, nearest…
We discuss the paramagnetic and Neel-ordered phases of the Kondo lattice Hamiltonian on the 2D square lattice by means of bond Fermions. In the doped case we find two antiferromagnetic solutions, the first one with small ordered moment,…
We study extended Hubbard model on a triangular lattice near doping $x=1/3$, which may be relevant for the recently discovered superconductor Na$_x$CoO$_2 \cdot y$H$_2$O. By generalizing this model to $N$ fermionic species, we formulate a…
Analysis of the electronic state of the CuO2 planes of high-Tc materials has been performed with special regard to the influence of the Coulomb interactions separated after moments. Different symmetry breaking effects were revealed. A…
The role of the multiorbital effects on the emergence of frustrated electronic orders on the triangular lattice at half filling is investigated through an extended spinless fermion Hubbard model. By using two complementary approaches,…
We theoretically study finite temperature properties of interacting fermion systems under geometrical frustration in the charge degree of freedom. Physical quantities such as charge structure factors, the specific heat, and the entropy, of…
In the studies of iron-pnictides, a key question is whether their bad-metal state from which the superconductivity emerges lies in close proximity with a magnetically ordered insulating phase. Recently it was found that at low temperatures,…
The electronic states of isostructural single-component molecular conductors [M(tmdt)2] (M= Ni, Au, and Cu) are theoretically studied. By considering fragments of molecular orbitals as basis functions, we construct a multiorbital model…
We consider a one-dimensional electron system, suitable for the description of the electronic correlations in a metallic carbon nanotube. Renormalization group methods are used to study the low-energy behavior of the unscreened Coulomb…
The phase diagram of non-hydrated Na(x)CoO(2) has been determined by changing the Na content x using a series of chemical reactions. As x increases from 0.3, the ground state goes from a paramagnetic metal to a charge-ordered insulator (at…
We describe a variational theory of multi-band two-dimensional electron gases that captures the interplay between electrostatic confining potentials, orbital-dependent interlayer electronic hopping and electron-electron interactions, and…
We study a one-dimensional extended Hubbard model with longer-range Coulomb interactions at quarter-filling in the strong coupling limit. We find two different charge-ordered ground states as the strength of the longer range interactions is…
`Quantum Charge Liquid'(QCL), a new phase, is proposed to describe anomalous metallic properties (T < 100 K)of a density 'y' of doped holes with strong coulomb repulsions, in a band insulator NaCoO$_2$ with N sites. This phase, a quantum…
Motivated by the various physical properties observed in $\theta$-(BEDT-TTF)$_2$X, we study the ground state of extended Hubbard model on two-dimensional anisotropic triangular lattice at 1/4-filling with variational Monte Carlo method. It…