LCAO model for 3D Fermi surface of high-Tc cuprate Tl2Ba2CuO6+δ
Department of Theoretical Physics, Faculty of Physics,
University of Sofia St. Clement of Ohrid, 5 J. Bourchier blvd., BG-1164 Sofia, Bulgaria
Published online: 1 December 2009
A simple analytical formula for three-dimensional Fermi surface (3D FS) of Tl2Ba2CuO6+δ is derived in the framework of LCAO approximation spanned over Cu 4s, Cu 3dx2-y2 , O 2px and O 2py states. This analytical result can be used for fitting of experimental data for 3D FS such as polar angle magnetoresistance oscillation. The model takes into account effective copper-copper hopping amplitude tss between Cu 4s orbitals from neighbouring CuO2 layers. The acceptable correspondence with the experimental data gives a hint that the tss amplitude dominates in formation of coherent 3D FS, and other oxygen-oxygen and copper-oxygen amplitudes are rather negligible. For absolute determination of the hopping parameters a simple electronic experiment with a field effect transistor type microstructure is suggested. The thin superconductor layer is the source-drain channel of the layered structure where an AC current is applied.
PACS: 71.15.Ap – Basis sets and related methodology / 73.43.Qt – Magnetoresistance / 74.72.Jt – Other cuprates, including Tl and Hg-based cuprates / 74.78.Fk – Multilayers, superlattices, heterostructures
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009