Energy and polarization dependence of resonant inelastic X-ray scattering in Nd2CuO4 Original Research Article

We report the energy and polarization dependence of resonant inelastic X-ray scattering from Nd2CuO4. An energy loss feature at ∼6 eV is observed in the vicinity of the Cu K-edge. Numerical calculations based on the Anderson impurity model identify this as a charge transfer excitation to the anti-bonding state. The incident polarization is shown to select the intermediate states participating in the resonance process. Resonances are observed at 8990 and 9000 eV with the incident polarization perpendicular and parallel to the CuO planes, respectively. In contrast to our single-site model calculations, no resonances are observed associated with the 3d10 intermediate states, suggesting that non-local effects play a role.