The electronic entropy of superconducting cuprates includes crucial information on the metallic state. In this context the electronic entropy of cuprates is calculated for the ${\mathrm{CuO}}_2$ layer in order to clarify the features of metallic states. It is shown that the observed peculiar doping dependence of electronic entropy can be explained by the Kamimura-Suwa model without introducing the pseudogap concept, while an ordinary band structure gives too small values even in the overdoped region. It is also shown that the observed anomalous behaviors in normal-state properties of cuprates such as resistivity and the Hall effect are explained by the Kamimura-Suwa model. From these results it is suggested that the hole carriers in cuprates form a metallic state by taking the Zhang-Rice singlet and Hund’s coupling triplet alternately in the presence of the local antiferromagnetic ordering.

• Received 10 July 2001

DOI:https://doi.org/10.1103/PhysRevB.66.054504