Related papers: Variation of Electron-electron interaction in pyro…
Electronic and magnetic properties of molybdenum pyrochlores A2Mo2O7 are studied by the fully relativistic density-functional theory plus on-site repulsion (U) method, with focusing on the spin-glass insulating material Y2Mo2O7. We find…
Superconductivity in intercalated graphite CaC6 and H under extreme pressure, in the framework of superconducting density functional theory, is discussed. A detailed analysis on how the electron-phonon and electron-electron interactions…
Recent theory and experiment have revealed that strong spin-orbit coupling can have dramatic qualitative effects on the band structure of weakly interacting solids. Indeed, it leads to a distinct phase of matter, the topological band…
We investigate the electronic and magnetic structures of two-dimensional transition metal tri-chalcogenide CrSiTe$_{3}$ and CrGeTe$_{3}$ materials by carrying out first-principles calculations. The single-layer CrSiTe$_3$ and CrGeTe$_3$ are…
The magnetic and electronic properties of Eu2Ru2O7 are discussed in terms of the local ruthenium and europium coordinations, electronic band structure calculations and molecular orbital energy levels. A preliminary electronic structure was…
We report electronic band structure calculations for Sr$_{4}$Ru$_{3}$O$_{10}$ that displays both ferromagnetic and metamagnetic behavior. The density functional calculations find the ground state to be ferromagnetic in agreement with the…
The interplay between long-range and local Coulomb repulsion in strongly interacting electron systems is explored through a two-dimensional Hubbard-Wigner model. An unconventional metallic state is found in which collective low-energy…
Experimental observations of anisotropic tightly bound excitons in black phosphorene, and correlated phenomena such as room temperature magnetically active edges in phosphorene nanoribbons (PNRs), sparked discussions on the controversial…
It is widely perceived that the correlation effect may play an important role in several unconventional superconducting families, such as cuprate, iron-based and heavy-fermion superconductors. The application of high pressure can tune the…
We discuss a general approach to a realistic theory of the electronic structure in materials containing correlated d- or f- electrons. The main feature of this approach is the taking into account the energy dependence of the electron…
Effects of the electron-electron interaction on tunneling into a metal in ultra-high magnetic field (ultra-quantum limit) are studied. The range of the interaction is found to have a decisive effect both on the nature of the field-induced…
Electronic correlation effects are manifested in quantum materials when either the onsite Coulomb repulsion is large or the electron kinetic energy is small. The former is the dominant effect in the cuprate superconductors or heavy fermion…
Carrier doping to the Mott insulator is essential to produce highly correlated metals with emergent properties. Pyrochlore ruthenates, Pr$_{2}$Ru$_{2}$O$_{7}$ (Ru-$4d$ electron number, $n=4$) and Ca$_{2}$Ru$_{2}$O$_{7}$ ($n=3$), are a Mott…
We have investigated the charge dynamics and the nature of many-body interactions in La- and Pr- doped CaFe2As2. From the infrared part of the optical conductivity, we discover that the scattering rate of mobile carriers above 200 K…
High-temperature superconductivity (HTSC) remains one of the most challenging and fascinating mysteries in condensed matter physics. Recently, superconductivity with transition temperature exceeding liquid-nitrogen temperature is discovered…
We discuss phenomena arising from the combined influence of electron correlation and spin-orbit coupling, with an emphasis on emergent quantum phases and transitions in heavy transition metal compounds with 4d and 5d elements. A common…
We use Ru $L_3$-edge resonant inelastic x-ray scattering (RIXS) to study the full range of excitations in Ca$_3$Ru$_2$O$_7$ from meV-scale magnetic dynamics through to the eV-scale interband transitions. This bilayer $4d$-electron…
Less common ligand coordination of transition-metal centers is often associated with peculiar valence-shell electron configurations and outstanding physical properties. One example is the Fe$^+$ ion with linear coordination, actively…
The electronic structure of the $(2\sqrt{2}\times\sqrt{2})R45^{\circ}$ O/Cu(001) system has been calculated using locally self-consistent, real space multiple scattering technique based on first principles. Oxygen atoms are found to perturb…
In frustrated magnetic systems, geometric constraints or the competition amongst interactions introduce extremely high degeneracy and prevent the system from readily selecting a low-temperature ground state. The most frustrated known spin…