We report detailed Fermi surface topology and quasiparticle dynamics of the host cobaltate Na0.7CoO2. A direct mapping of the Fermi surface is carried out by angle-resolved photoemission spectroscopy (ARPES). Fermi surface at temperature 16K is a hole-pocket centered around the Gamma-point. The highly correlated nature of the electron liquid is evidenced from strong on-site Coulomb interaction seen through a valence satellite and via renormalization of the quasiparticle dispersion. The quasiparticle exhibits spectral coherence only below 150K which includes the non-Fermi liquid regime.
@article{arxiv.cond-mat/0605289,
title = {Low-lying electronic structure of doped triangular cobaltates},
author = {A. P. Kuprin and D. Qian and Y. -D. Chuang and M. Foo and R. J. Cava and M. Z. Hasan},
journal= {arXiv preprint arXiv:cond-mat/0605289},
year = {2009}
}