Electron Correlation Effects in Resonant Inelastic X-ray Scattering of NaV2O5

Abstract

Element- and site-specific resonant inelastic x-ray scattering spectroscopy (RIXS) is employed to investigate electron correlation effects in {$\mathrm{Na}{\mathrm{V}}_2{\mathrm{O}}_5$}. In contrast to single photon techniques, RIXS at the vanadium $L_3$ edge is able to probe $d-d^{\ast }$ transitions between V d-bands. A sharp energy loss feature is observed at -1.56 eV, which is well reproduced by a model calculation including correlation effects. The calculation identifies the loss feature as excitation between the lower and upper Hubbard bands and permits an accurate determination of the Hubbard interaction term $U=3.0\pm 0.2$ eV.

15 pages, four figures, accepted to Phys. Rev. Lett