相关论文: Ab initio calculation of d-d excitations in quasi-…
The activation cross sections of (d,p), (d,2n), (d,3n), and (d,2p) reactions on 63,65Cu were measured in the energy range from 4 to 20 MeV using the stacked-foils technique. Then, following the available elastic-scattering data analysis…
Low-energy electron excitation spectra were measured on a single crystal of a typical iron-based superconductor PrFeAsO$_{0.7}$ using resonant inelastic X-ray scattering (RIXS) at the Fe-$L_3$ edge. Characteristic RIXS features are clearly…
Superconductivity appears to compete against the spin-density-wave in Fe pnictides. However, optimally cobalt doped samples show a quasi-two-dimensional spin excitation centered at the (0.5, 0.5, L) wavevector, "the spin resonance peak",…
Many computational models have been developed to predict the rates of atomic displacements in two-dimensional (2D) materials under electron beam irradiation. However, these models often drastically underestimate the displacement rates in 2D…
High resolution resonant inelastic x-ray scattering (RIXS) has proven particularly effective in the determination of crystal field and spin excitations in cuprates. Its strength lies in the large Cu $L_{3}$ resonance and in the fact that…
The ladder compound Sr$_{14}$Cu$_{24}$O$_{41}$ is of interest both as a quasi-one-dimensional analog of the superconducting cuprates and as a superconductor in its own right when Sr is substituted by Ca. In order to model resonant inelastic…
We report a comprehensive Cu L$_3$-edge resonant x-ray scattering study of two- and three-dimensional (2D and 3D) incommensurate charge correlations in single crystals of the underdoped high-temperature superconductor…
The electronic structure of CoO is studied by resonant inelastic soft X-ray scattering spectroscopy using photon energies across the Co 2p absorption edges. The different spectral contributions from the energy-loss structures are identified…
High resolution resonant inelastic x-ray scattering has been performed to reveal the role of lattice-coupling in a family of quasi-1D insulating cuprates, Ca$_{2+5x}$Y$_{2-5x}$Cu$_5$O$_{10}$. Site-dependent low energy excitations arising…
We present the first calculation of the electron-energy loss spectrum of infinite one-dimensional undoped CuO_3 chains within a multi-band Hubbard model. The results show good agreement with experimental spectra of Sr_2CuO_3. The main…
Motivated by the recent synthesis of Ba$_2$CuO$_{3+\delta}$ (BCO), a high temperature superconducting cuprate with putative $d_{3z^2-r^2}$ ground state symmetry, we investigated its electronic structure by means of Cu $L_3$ x-ray absorption…
Low-dimensional copper oxide lattices naturally manifest electronic states with strong short range quantum entanglement, which are known to lead to remarkable emergent material properties. However the nanometer scale many-body wavefunction…
On the basis of the first-principles evolutionary crystal structure prediction of stable compounds in the Cu-F system, we predict two experimentally unknown stable phases -- Cu2F5 and CuF3. Cu2F5 comprises two interacting magnetic…
We show that the dynamical screening of the Coulomb interaction among Cu-d electrons in high-Tc cuprates is very strong and that a proper treatment of this effect is essential for a consistent description of the electronic structure. In…
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…
BiFeO$_3$ is a multiferroic material featuring ferroelectricity and noncollinear antiferromagnetism. Definitive and efficient control of the characteristic spin texture of BiFeO$_3$ is attractive for emerging quantum devices. In this…
The orbital, lattice, and spin ordering phenomena in KCuF3 are investigated by means of LDA+U calculations, based on ab-initio pseudopotentials.We examine the Cu-3d orbital ordering and the associated Jahn-Teller distortion in several…
We study the electronic excitations near the charge-transfer gap in insulating CuO$_2$ planes, starting from a six-band model which includes $% p_\pi $ and $d_{xy}$ orbitals and Cu-O nearest-neighbor repulsion $U_{pd}$. While the low lying…
We present a detailed calculation of the magnetic couplings between nearest-neighbor and next-nearest-neighbor coppers in the edge-sharing geometry, ubiquitous in many cuprates. In this geometry, the interaction between nearest neighbor…
We study theoretically the resonant inelastic x-ray scattering in quasi-one-dimensional insulating copper oxides, where the incident photon energy is tuned to the Cu1s-4p absorption energy. Our attention is focused particularly on the…