Electronic structure of CuO2 planes: From insulator to superconductor
نویسندگان
چکیده
Using angle-resolved photoemission and linearly polarized synchrotron radiation, we measured the electronic band structure of electronic states of CuO2 plane materials ranging from insulators ~Sr2CuO2Cl2) to overdoped superconductors ~Bi2Sr2CaCu2O81x). We report three results: ~i! The CuO2 containing insulator possesses a spin-density-wave ~SDW! ground state; ~ii! there are precursors of the SDW state for underdoped Bi2Sr2CaCu2O81x ; ~iii! an extended saddle-point-type van Hove singularity is neither a necessary nor a sufficient condition for a high superconducting transition temperature, Tc . @S0163-1829~97!50226-8#
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