Fig. 2

Calculated Cu \(L_3\)-edge RIXS spectra with the spin-flip and non-spin-flip processes. (a,b) RIXS spectra for various in-plane momenta \({\bf{q}}_{\Vert }\) and photon energy \(\omega _i\) tuned to the absorption edge \(\omega _\textrm{edge}\) and \(\omega _0\sim 0.28\) eV with which the integrated intensity for \(\Delta S=0\) is maximum. RIXS spectra are presented by the calculated spectral weights, i.e., the \(\delta\)-functions shown by the vertical thin solid lines, after convolution with Lorentzian broadening of 0.2t. Spectra are vertically offset for clarity. (c) Photon energy \(\omega _i\) dependence of the integrated RIXS intensity with \(\Delta S=0\) (red) and 1 (blue) at \({\bf{q}}_{\Vert }=(\frac{\pi }{2},0)\), as well as the calculated XAS (gray). \(\omega _\textrm{edge}\) and \(\omega _0\) are marked by the blue and red arrows, respectively. (d)  Spin configurations with the largest weights in the XAS edge state indicated by the blue arrow in (c). The core holes in the RIXS intermediate state are created in the down-spin sublattice. (e)  Spin configurations with the largest weights in an eigenstate near the energy indicated by the red arrow in (c). The core holes in the RIXS intermediate state are created in the up-spin sublattice.