We have performed resonant inelastic x-ray scattering (RIXS) near the Cu-K edge on cuprate superconductors La2-xSrxCuO4, La2-xBaxCuO4, La2-xSr xCu1-yFeyO4, and Bi 1.76Pb0.35Sr1.89CuO6+δ, covering underdoped to heavily overdoped regimes and focusing on charge excitations inside the charge-transfer gap. RIXS measurements of the 214 systems with Ei=8.993 keV have revealed that the RIXS intensity at 1-eV energy transfer has a minimum at (0,0) and maxima at (±0.4π,0) and (0,±0.4π) for all doping points regardless of the stripe-ordered state, suggesting that the corresponding structure is not directly related to stripe order. Measurements with Ei=9.003 keV on metallic La 1.7Sr0.3CuO4 and Bi1.76Pb 0.35Sr1.89CuO6+δ exhibit a dispersive intraband excitation below 4 eV, similar to that observed in the electron-doped Nd1.85Ce0.15CuO4. This is the first observation of a dispersive intraband excitation in a hole-doped system, evidencing that both electron- and hole-doped systems have a similar dynamical charge correlation function.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2013 Mar 12|