Quasiparticle dispersion near the Fermi surface in NaxCoO2

✍ Scribed by A. Bourgeois; A.A. Aligia; T. Kroll; M.D. Núñez-Regueiro

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 543 KB
• Volume: 460-462
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2007.03.342

✦ Synopsis

We construct an effective Hamiltonian for the motion of t 2g highly correlated states in Na x CoO 2 . This three-band model includes the indirect Co-O-Co hopping t and the crystal-field splitting 3D. Calculations in a CoO 6 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 agree with angle-resolved photoemission experiments, in contrast to predictions using the local-density approximation.