Fig. 2: X-ray absorption spectra, and energy profiles of the resonant reflections in La3Ni2O7-δ.
From: Resolving the electronic ground state of La3Ni2O7-δ films
a The X-ray absorption spectra (XAS) and X-ray linear dichroism (XLD) near the O-K edge for Film 1 (red color) and Film 2 (blue color). The XAS are offset for clarity. Iab and Ic represent in-plane and out-of-plane XAS intensity, respectively. The XLD signal is obtained by subtracting the in-plane and out-plane XAS intensity. The inset orbitals illustrate the origins of the peak and dip features. b Schematic density of states of La3Ni2O7 and the corresponding bonding and antibonding orbitals. UHB and LHB represent the upper and lower Hubbard bands, respectively. c Energy profiles of the resonant reflection at (1/4, 1/4, 1.9) near the Ni-L3 absorption edge with π- and σ-polarizations, and the peak intensity is maximized at E = 852.2 eV. Error bars are obtained from the Lorentzian fitting of RXS peaks. d Energy scans at constant wavevector on and off the QSP = (1/4, 1/4, 1.9) using different photon polarizations for two La3Ni2O7-δ films. The solid (dashed) lines correspond to the π (σ) polarization. The curves are offset for clarity.
