相关论文: Molecular orbital excitations in cuprates

We carry out a detailed study of the role of electronic interaction on $p$ oxygen orbitals in a Mott insulator oxide (UO$_2$) and a charge transfer oxide (TiO$_2$). First, we calculate values of effective interactions \Uff, \Upp{} and…

Core excitation from terminal oxygen O$_T$ in O$_3$ is shown to be an excitation from a localized core orbital to a localized valence orbital. The valence orbital is localized to one of the two equivalent chemical bonds. We experimentally…

Estimating many-body effects that deviate from an independent particle approach, has long been a key research interest in condensed matter physics. Layered cuprates are prototypical systems, where electron-electron interactions are found to…

This paper derives the anisotropic superexchange interactions from a Hubbard model for excitations within the copper 3d band and the oxygen 2p band of the undoped insulating cuprates. We extend the recent calculation of Yildirim et al.…

We develop a formalism for calculating resonant inelastic x-ray scattering (RIXS) spectra in systems of itinerant electrons with arbitrary band structures, accounting for the effect of the positively-charged core hole exactly. We apply this…

We consider a polaron model where molecular \emph{rotations} are important. Here, the usual hopping between neighboring sites is affected directly by the electron-phonon interaction via a {\em twist-dependent} hopping amplitude. This model…

We studied the relationship between the charge doping and the correlation, and its effects on the spectral function of the BaFe$_2$As$_2$ compound in the framework of the density functional theory combined with the dynamical mean field…

We theoretically examine the momentum dependence of resonant inelastic x-ray scattering (RIXS) spectrum for one-dimensional and two-dimensional cuprates based on the single-band Hubbard model with realistic parameter values. The spectrum is…

In high Tc superconductors the magnetic and electronic properties are determined by the probability that valence electrons virtually jump from site to site in the CuO2 planes, a mechanism opposed by on-site Coulomb repulsion and favored by…

We investigate a model for the CuO_2 plane of high-T_c superconductors where the charge carriers are coupled to A_{1g} and B_{1g} symmetric out-of plane vibrations of the oxygen atoms in the presence of local Hubbard correlations. The…

The study of elementary bosonic excitations is essential toward a complete description of quantum electronic solids. In this context, resonant inelastic X-ray scattering (RIXS) has recently risen to becoming a versatile probe of electronic…

We develop a gauge-independent perturbation theory for the grand potential of itinerant electrons in two-dimensional tight-binding models in the presence of a perpendicular magnetic field. At first order in the field, we recover the result…

A model of CuO$_2$ planes of cuprate perovskites, containing $d_{x^2-y^2}$ copper orbitals and symmetric combinations of oxygen $p_\sigma$ orbitals, is investigated using the strong coupling diagram technique. This approach allows one to…

Scattering of electrons by localized spins is the ultimate process enabling electrical detection and control of the magnetic state of a spin-doped material. At the molecular scale, this scattering is mediated by the electronic orbitals…

In strongly correlated systems the strength of Coulomb interactions between electrons, relative to their kinetic energy, plays a central role in determining their emergent quantum mechanical phases. We perform resonant x-ray scattering on…

Unraveling the behavior of the electrons in the copper-oxygen planes of cuprate superconductors remains a challenge. Here we examine the electronic charge redistribution among planar copper and oxygen orbitals and the charge gap using the…

Neutron scattering studies have provided important information about the momentum and energy dependence of magnetic excitations in cuprate superconductors. Of particular interest are the recent indications of a universal magnetic excitation…

We investigate the nature of the electronic ground state and electron-lattice couplings for doped chains of CuO_4 plaquettes or CuO_6 octahedra. The undoped configuration implies here Cu 3d^9 and O 2p^6 formal valence states. The results of…

Using resonant inelastic x-ray scattering (RIXS) at the Cu $L$-absorption edge, we have observed intense, dispersive spin excitations in highly overdoped Tl$_2$Ba$_2$CuO$_{6+\delta}$ (superconducting $T_c =6$ K), a compound whose…

The collective spin and charge excitations of doped cuprates and their relationship to superconductivity are not yet fully understood, particularly in the case of the charge excitations. Here, we study the doping-dependent dynamical spin…