Coulomb correlations do not fill the e′g hole pockets in Na0.3CoO2
Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich, Germany
2 College of Humanities and Sciences, Nihon University, and CREST JST, Tokyo, 156, Japan
Revised: 9 January 2008
Published online: 13 March 2008
There exists presently considerable debate over the question whether local Coulomb interactions can explain the absence of the small e′g Fermi surface hole pockets in photoemission studies of Na0.3CoO2. By comparing dynamical mean field results for different single particle Hamiltonians and exact diagonalization as well as quantum Monte Carlo treatments, we show that, for realistic values of the Coulomb energy U and Hund exchange J, the e′g pockets can be slightly enhanced or reduced compared to band structure predictions, but they do not disappear.
PACS: 71.18.+y – Fermi surface: calculations and measurements; effective mass, g factor / 71.27.+a – Strongly correlated electron systems; heavy fermions / 74.70.-b – Superconducting materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008