Europhys. Lett.
Volume 68, Number 3, November 2004
Page(s) 433 - 439
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 09 October 2004
Europhys. Lett., 68 (3), pp. 433-439 (2004)
DOI: 10.1209/epl/i2004-10254-x

A tight-binding investigation of the $\chem{Na_{\it x}CoO_2}$ Fermi surface

M. D. Johannes, D. A. Papaconstantopoulos, D. J. Singh and M. J. Mehl

Code 6391, Naval Research Laboratory - Washington, D.C. 20375, USA

received 22 March 2004; accepted in final form 5 August 2004
published online 9 October 2004

We perform an orthogonal basis tight-binding fit to an LAPW calculation of paramagnetic Na xCoO 2 for several dopings. The optimal position of the apical oxygen at each doping is resolved, revealing a non-trivial dependence of the band structure and Fermi surface on oxygen height. We find that the small eg' hole pockets are preserved throughout all investigated dopings and discuss some possible reasons for the lack of experimental evidence for these Fermi sheets.

71.20.-b - Electron density of states and band structure of crystalline solids.
71.18.+y - Fermi surface: calculations and measurements, effective mass, g-factor.

© EDP Sciences 2004