Nature of the Electronic States near the Fermi Level in High-Tc Superconductors: High-Energy Spectroscopic Evidence
Based on the results of recent photoemission and other spectroscopic studies on pure and doped Cu and Ni oxides, the origin of the electronic states near the Fermi level (EF) in high-Tc superconductors is discussed. It is pointed out that the location and symmetry of localized holes or electrons at low doping levels may not be necessarily the same as those of itinerant carriers responsible for superconductivity. The singlet state 1A1 of the CuOn local cluster or the impurity Anderson model is likely to be the origin of itinerant carriers in the doped Cu oxides.
KeywordsAnisotropy Sera SrCl Hongo
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