Quasiparticle dispersion near the Fermi surface in Na${}_x$CoO${}_2$

Abstract

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.

2 pages, 2 figures, to be published in Proceedings of M2S HTSC Dresden 2006

References in corpus (4)

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