@article{oai:niigata-u.repo.nii.ac.jp:00002257,
 author = {Ono, Yoshiaki},
 issue = {Part 2},
 journal = {Physica. C, Superconductivity, Physica. C, Superconductivity},
 month = {Sep},
 note = {We investigate the electronic state of the 11 band d–p model on the two-dimensional triangular lattice simulating a CoO2 plane in the layered cobalt oxides such as NaxCoO2 and NaxCoO2 · yH2O. The tight-binding parameters are determined so as to fit the LDA band structure. Using the slave boson approach together with the 1/N expansion method, we obtain the renormalized quasiparticle bands, where the a1g band with a large hole Fermi surface is largely renormalized due to the strong correlation effect, while the eg' bands with six hole pockets are almost unchanged. We also discuss the metal–insulator transition (MIT) with varying the d–p charge transfer energy Δ, and find that the MIT takes place at a critical value Δc = 4.01 eV.},
 pages = {1047--1048},
 title = {Electronic states and metal-insulator transition in the triangular lattice d-p model for layered cobaltates},
 volume = {460-462},
 year = {2007}
}