Intermediate dimensional character of charge transfer excitation modes in a two-leg cuprate ladder

Plasmons and Interband Transitions of Ca$_{11}$Sr$_3$Cu$_{24}$O$_{41}$ investigated by Electron Energy-Loss Spectroscopy

“…Thus, the excitation between 3 -4 eV is most likely a result from electronic excitations in the Cu-O ladders. The results of recent resonant inelastic x-ray scattering (RIXS) of Ca x Sr 14−x Cu 24 O 41 [46][47][48] are in very good agreement with our assignment of the spectral structures at 3 to 5 eV as seen by EELS. We note that, ignoring the resonance process in RIXS, EELS and RIXS probe the same dynamic response function.…”

Evidence for an orbital dependent Mott transition in the ladders of (La,Ca)$_x$Sr$_{14-x}$Cu$_{24}$O$_{41}$ derived by electron energy-loss spectroscopy

“…The results of resonant inelastic x-ray scattering (RIXS) of Ca x Sr 14−x Cu 24 O 41 (Ref. [35][36][37]) are in good agreement with our assignment of the spectral structures in the energy range between 2 -5 eV.…”

“…In the energy range 2 -3 eV there are dispersive excitations which according to our previous studies of the one dimensional corner sharing CuO 3 and CuO 2 chain compounds Sr 2 CuO 3 and SrCuO 2 [27,34], were ascribed to more delocalized charge transfer excitations [35][36][37], also detected in 2D cuprates. These excitations are more pronounced for q parallel to the a-axis compared to q parallel to the c-axis (see supplementary information and Fig.…”