Polarized Cu L3-edge x-ray absorption spectra of a single crystal of YBa2Cu3O6.8 have been measured to determine the symmetry of the orbital of the electronic holes induced by doping. The states induced by doping in YBa2Cu3O7-δ (0<δ<~0.5) have been found to be ligand holes L*, giving the 3d9L* configuration, and their weight is correlated with Tc. The polarization dependence shows that the hole L*, induced by doping, is found to be mainly in the Cu-O orbital oriented along the c axis involving the O 2pz orbital of & orbitals. This result indicates the important role of BaO layers and shows that theories of high-Tc superconductivity have to take account of a second band with different symmetry, beyond the single band (the two-dimensional band & and O 2px,2py orbitals in the a-b plane of the CuO2 layers) usually considered in models of the electronic structure of high-Tc superconductors.
Symmetry of the 3d9 Ligand Hole Induced By Doping In Yba2cu3o7-delta
DI CICCO, Andrea;
1988-01-01
Abstract
Polarized Cu L3-edge x-ray absorption spectra of a single crystal of YBa2Cu3O6.8 have been measured to determine the symmetry of the orbital of the electronic holes induced by doping. The states induced by doping in YBa2Cu3O7-δ (0<δ<~0.5) have been found to be ligand holes L*, giving the 3d9L* configuration, and their weight is correlated with Tc. The polarization dependence shows that the hole L*, induced by doping, is found to be mainly in the Cu-O orbital oriented along the c axis involving the O 2pz orbital of & orbitals. This result indicates the important role of BaO layers and shows that theories of high-Tc superconductivity have to take account of a second band with different symmetry, beyond the single band (the two-dimensional band & and O 2px,2py orbitals in the a-b plane of the CuO2 layers) usually considered in models of the electronic structure of high-Tc superconductors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
