We construct an effective Hamiltonian for the motion of t2g highly correlated states in NaxCoO2. This three-band model includes the indirect Co-O-Co hopping t and the crystal-field splitting 3D. Calculations in a CoO6 cluster give the effective parameters t=100 meV and 3D=315 meV. The Hamiltonian is solved using a generalized slave-boson mean-field approximation. The results show a significant band renormalization. Without any additional hypothesis, the dispersion of the bands near the Fermi energy and Fermi surface topology agrees with angle-resolved photoemission experiments, in contrast to predictions using the local-density approximation.
@article{arxiv.cond-mat/0609759,
title = {Quasiparticle dispersion near the Fermi surface in Na$_x$CoO$_2$},
author = {A. Bourgeois and A. A. Aligia and T. Kroll and M. D. Núñez-Regueiro},
journal= {arXiv preprint arXiv:cond-mat/0609759},
year = {2009}
}
Comments
2 pages, 2 figures, to be published in Proceedings of M2S HTSC Dresden 2006