Related papers: Charge and orbital excitations in Li2CuO2
We investigate electronic excitations in La2-x(Br,Sr)xCuO4 using resonant inelastic x-ray scattering (RIXS) at the oxygen K edge. RIXS spectra of the hole-doped cuprates show clear momentum dependence below 1 eV. The spectral weight…
Spin excitations of layered copper oxide show various characteristic features, depending on the carrier concentration. In this study, we conducted inelastic neutron scattering (INS) measurements on La$_{2-x}$Sr$_{x}$CuO$_4$ (LSCO), with $x$…
A consistent description of low-energy charge and spin responses of the insulating Sr_2CuO_2Cl_2 lamellar system is found in the framework of a one-band Hubbard model which besides $U$ includes hoppings up to 3^{rd} nearest-neighbors. By…
We report a resonant inelastic x-ray scattering (RIXS) study of charge excitations in the electron-doped high-Tc superconductor Nd1.85Ce0.15CuO4. The intraband and interband excitations across the Fermi energy are separated for the first…
We report on the observation of orbital excitations in YVO3 by means of resonant inelastic x-ray scattering (RIXS) at energies across the vanadium L3 and oxygen K absorption edges. Due to the excellent experimental resolution we are able to…
Multi-band Mott insulators with moderate spin-orbit and Hund's coupling are key reference points for theoretical concept developments of correlated electron systems. The ruthenate Mott insulator Ca$_{2}$RuO$_{4}$ has therefore been…
To determine the strength of essential electronic and magnetic interactions in the iridates Sr$_2$IrO$_4$ and Ba$_2$IrO$_4$ - potential platforms for high-temperature superconductivity - we use many-body techniques from wavefunction-based…
We performed inelastic neutron scattering on the 2D Shastry-Sutherland system SrCu2(11BO3)2 with an exact dimer ground state. Three energy levels at around 3, 5 and 9 meV were observed at 1.7 K. The lowest excitation at 3.0 meV is almost…
A semi-quantitative cluster approach is developed to describe the charge transfer (CT) electron-hole excitations in insulating cuprates in a rather wide energy range up to 10- 15 eV. It generalizes the Zhang-Ng (ZN) model of CT excitons by…
We study charge excitation spectra in the two-dimensional $t$-$J$ model on a square lattice to explore a charge-order tendency recently found in electron-doped cuprates around the carrier density 0.15. The static susceptibility of $d$-wave…
We report an Fe $K$-edge resonant inelastic X-ray scattering (RIXS) study of K$_{0.83}$Fe$_{1.53}$Se$_2$. This material is an insulator, unlike many parent compounds of iron-based superconductors. We found a sharp excitation around 1 eV,…
Very high energy resolution photoemission experiments on high quality samples of optimally doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ show new features in the low-energy electronic excitations. A marked change in the binding energy and…
The charge and spin correlations in La$_{1.875}$Ba$_{0.125}$CuO$_4$ (LBCO 1/8) are studied using Cu $L_3$ edge resonant inelastic x-ray scattering (RIXS). The static charge order (CO) is observed at a wavevector of $(0.24,0)$ and its charge…
By means of resonant inelastic x-ray scattering at the Cu L$_3$ edge, we measured the spin wave dispersion along $\langle$100$\rangle$ and $\langle$110$\rangle$ in the undoped cuprate Ca$_2$CuO$_2$Cl$_2$. The data yields a reliable estimate…
We present a study of the charge-transfer excitations in undoped Nd2CuO4 using resonant inelastic X-ray scattering (RIXS) at the Cu K-edge. At the Brillouin zone center, azimuthal scans that rotate the incident-photon polarization within…
We have investigated the electronic structure of the zigzag ladder (chain) compound SrCuO2 combining polarized optical absorption, reflection, photoreflectance and pseudo-dielectric function measurements with the model calculations. These…
We report on the Cu 1s resonant inelastic X-ray scattering (RIXS) of Cu-O one-dimensional (1D) strongly correlated insulator systems with contrasting atomic arrangements, namely edge-sharing CuGeO3 and corner-sharing Sr2CuO3. Owing to good…
Electron-hole pair excitations in the insulating cuprates $Sr_2CuO_2Cl_2$ were investigated by angle-resolved electron energy loss spectroscopy. The optically allowed and optically forbidden transitions were observed to be strongly…
A resonant inelastic x-ray scattering study of the electronic structure of the semiconductor cuprous oxide, $\rm Cu_2O$, is reported. When the incident x-ray energy is tuned to the Cu K-absorption edge, large enhancements of the spectral…
We present calculations for resonant inelastic x-ray scattering (RIXS) in edge-shared copper oxide systems, such as CuGeO$_{3}$ and Li$_{2}$CuO$_{2}$, appropriate for hard x-ray scattering where the photoexcited electron lies above oxygen…