Crossing the gap from p- to n-type doping : Nature of the states near the chemical potential in La2-xSrxCuO4 and Nd2-xCexCuO4-delta

We report on an x-ray absorption and resonant photoemission study on single crystals of the high-T-c cuprates La2-xSrxCuO4 and Nd2-xCexCuO4-delta. Using an intrinsic energy reference, we find that ...