Related papers: Electronic States in Two-Dimensional Triangular Co…

We investigate the electronic states and the transport properties of the CoO2 plane in NaxCoO2 on the basis of the two-dimensional triangular lattice 11-band d-p model by using the fluctuation exchange approximation, where we consider the…

Measurements of polarization-dependent soft x-ray absorption reveal that the electronic states determining the low-energy excitations of Na$_{x}$CoO$_2$ have predominantly $a_{1g}$ symmetry with significant O $2p$ character. A large…

Effects of Coulomb correlation on LaOFeAs electronic structure have been investigated by LDA+DMFT(QMC) method. The calculation results show that LaOFeAs is in the regime of intermediate correlation strength with significant part of the…

We analyzed the effects of a spin voltage as well as a conventionally applied voltage in a QD system with a different number of quantum states in the dot region in presence of Coulombic interaction between the quantum dot and two leads. We…

The electronic structure of Sr0.35CoO2, structurally analogous to the layered NaxCoO2, has been evaluated using the local spin density approximation (LSDA). We find that evident c-dispersions appear in both the e'g and a1g Co-derived bands,…

We investigate the low temperature magnetic field dependence of the resistivity in the thermoelectric misfit cobalt oxide [Bi1.7Ca2O4]0.59CoO2 from 60 K down to 3 K. The scaling of the negative magnetoresistance demonstrates a spin…

We report a first-principles projector augmented wave (PAW) study on Na$_{0.5}$CoO$_2$. With the sodium ion ordered insulating phase being identified in experiments, pure density functional calculations fail to predict an insulating ground…

We consider possible routes to superconductivity in hydrated cobaltates Na_xCoO_2.yH_2O on the basis of the t-J-V model plus phonons on the triangular lattice. We studied the stability conditions for the homogeneous Fermi liquid (HFL) phase…

Engineered $Na_{0.75}CoO_2$ is considered a prime candidate to achieve high-efficiency thermoelectric systems to regenerate electricity from waste heat. In this work, three elements with outmost electronic configurations, (1) an open d…

Coulomb interactions among charge carriers that occupy an electronic flat band have a profound impact on the macroscopic properties of materials. At sufficient strength, these interactions can give rise to captivating phenomena such as…

In this work, we investigate the adsorption of a single cobalt atom (Co) on graphene by means of the complete active space self-consistent field approach, additionally corrected by the second-order perturbation theory. The local structure…

We report a precise $^{59}$Co nuclear quadrupolar resonance (NQR) measurement on the recently discovered cobalt oxyhydrate Na$_{0.35}$CoO$_{2}$$\cdot y$H$_{2}$O superconductor from $T$=40 K down to 0.2 K. We find that in the normal state…

The electronic band structures of the parent compound Na0.3CoO2 and the hydrated superconductor Na0.3CoO2.1.3H2O were evaluated using the local spin density approximation (LSDA). Systematic analysis on the bands near the Fermi surface (FS)…

Puzzling properties of sodium cobaltates Na${}_x$CoO${}_2$ become an issue of numerous recent theoretical and experimental investigations because of very high thermopower and intricate phase diagram of this material. Experiments indicated…

Density functional theory (DFT) within the local density approximation (LDA) is used to understand the electronic properties of Na1/3CoO2 and Na1/3CoO2(H2O)4/3, which was recently found to be superconducting1. Comparing the LDA charge…

We report T_c and ^{59}Co nuclear quadrupole resonance (NQR) measurements on the cobalt oxide superconductor Na_{x}CoO_{2}\cdot 1.3H_{2}O (T_c=4.8 K) under hydrostatic pressure (P) up to 2.36 GPa. T_c decreases with increasing pressure at…

The structure of the low-energy electronic states in layered cobaltates is considered starting from the Mott insulating limit. We argue that the coherent part of the wave-functions and the Fermi-surface topology at low doping are strongly…

We used ab-initio quantum chemical methods, treating explicitly the strong correlation effects within the cobalt 3d shell, as well as the screening effects on the effective integrals, for accurately determining on-site and nearest-neighbor…

We present an analytically solvable model of $P$ colinear, two-dimensional quantum dots, each containing two electrons. Inter-dot coupling via the electron-electron interaction gives rise to sets of entangled ground states. These ground…

We report the electronic structure of monoclinic CuO as obtained from first principles calculations utilizing density functional theory plus effective Coulomb interaction (DFT + U) method. In contrast to standard DFT calculations taking…