相关论文: Charge-transfer exciton in La2CuO4 probed with res…
We report a resonant inelastic x-ray scattering study of the dispersion relations of charge transfer excitations in insulating La$_2$CuO$_4$. These data reveal two peaks, both of which show two-dimensional characteristics. The lowest energy…
We provide a semiquantitative explanation of a recent experiment on the resonant inelastic x-ray scattering (RIXS) in insulating cuprate La2CuO4 (Y.J. Kim et al., Phys. Rev. Lett. 89, 177003 (2002).). We show theoretically that there are…
We report a resonant inelastic x-ray scattering study of electronic excitations in Li_2CuO_2, an insulating compound comprised of ribbons of edge-sharing copper-oxygen chains. Three excitations, which show little dependence on momentum…
We use resonant inelastic x-ray scattering to investigate charge-stripe correlations in La$_{1.675}$Eu$_{0.2}$Sr$_{0.125}$CuO$_4$. By differentiating elastic from inelastic scattering, it is demonstrated that charge-stripe correlations…
We present a detailed Cu K-edge resonant inelastic X-ray scattering (RIXS) study of the Mott insulator La2CuO4 in the 1-7 eV energy transfer range. As initially found for the high-temperature superconductor HgBa2CuO4+d, the spectra exhibit…
Results of model calculations using exact diagonalization reveal the orbital character of states associated with different Raman loss peaks in Cu $K$-edge resonant inelastic X-ray scattering (RIXS) from La$_{2}$CuO$_{4}$. The model includes…
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 report resonant inelastic x-ray measurements of insulating La$_2$CuO$_4$ and Sr$_2$CuO$_2$Cl$_2$ taken with the incident energy tuned near the Cu K absorption edge. We show that the spectra are well described in a shakeup picture in 3rd…
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 performed resonant inelastic x-ray scattering (RIXS) near the Cu-K edge on cuprate superconductors La(2-x)Sr(x)CuO(4), La(2-x)Ba(x)CuO(4), La(2-x)Sr(x)Cu(1-y)Fe(y)O(4) and Bi(1.76)Pb(0.35)Sr(1.89)CuO(6+d), covering underdoped to…
We report a resonant inelastic x-ray scattering (RIXS) study of the doping dependence of charge-transfer excitations in $\rm La_{2-x}Sr_xCuO_4$. The mome ntum dependence of these charge excitations are studied over the whole Brillouin zone…
Resonant soft X-ray scattering with photon energies near the O K and the Cu L3 edges was used to study charge ordering in the system La_{1.8-x}Eu_{0.2}Sr_xCuO_4 as a function of temperature for x = 0.125 and 0.15. From the superstructure…
The insulator-to-metal transition continues to be a challenging subject, especially when electronic correlations are strong. In layered compounds, such as La2-xSrxNiO4 and La2-xBaxCuO4, the doped charge carriers can segregate into…
We analyze the resonant inelastic x-ray scattering (RIXS) spectra at the Cu and Ni K edges in La2CuO4 and La2NiO4, respectively. We make use of the Keldysh-Green-function formalism, in which the RIXS intensity is described by a product of…
We report a Cu K-edge resonant inelastic x-ray scattering (RIXS) study of momentum-dependent charge excitations in Nd$_{2-x}$Ce$_x$CuO$_4$ ($x$ = 0.075 and 0.18). The peak position and width of the excitations coincide excellently with…
We report the first observation of soft-x-ray scattering from spin fluctuations in a high-Tc parent compound. An antiferromagnetic charge transfer insulator, CaCuO2, was irradiated by Cu M-edge soft x-rays. Ultra-high resolution…
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…
We have measured the energy and momentum dependent loss function of Li_2CuO_2 single crystals by means of electron energy-loss spectroscopy in transmission. Using the same values for the model parameters, the low-energy features of the…
We report a high-resolution resonant inelastic soft x-ray scattering study of the quantum magnetic spin-chain materials Li2CuO2 and CuGeO3. By tuning the incoming photon energy to the oxygen K-edge, a strong excitation around 3.5 eV energy…
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…