Analysis of resonant inelastic X-ray scattering in stripe-ordered nickelate

Nomura, Takuji; Kaneshita, Eiji*

We analyze theoretically the resonant inelastic X-ray scattering (RIXS) at the Ni edge in the stripe-ordered state of LaSrNiO at = 1/3. In the calculation of RIXS spectra, the stripe-ordered ground state is described within the Hartree-Fock approximation by using a realistic tight-binding model for Ni 3 and O 2 orbitals, and the electron correlations in the electronic excitation processes are taken into account within the random-phase approximation. The calculated RIXS spectrum shows a tail toward the low-energy region when the momentum transfer of photons equals the stripe vector , being consistent with a recent experimental result. The origin of this anomalous momentum dependence of RIXS spectra is discussed microscopically.