Europhys. Lett, 34 (9), pp. 693-698 (1996)
Spectral properties of two-dimensional Hubbard model with anisotropic hopping
V. Zlatic , P. Entel and S. Grabowski
Physics Department, Georgetown University - Washington, DC 20057, USA
Physics Department, Duisburg University - 47048 Duisburg, Germany
(received 12 February 1996; accepted in final form 2 May 1996)
PACS. 71.20 - Electron density of states.
PACS. 79.60 - Photoemission and photoelectron spectra.
Abstract:The zero-temperature spectral properties and Fermi surface (FS) anomalies of hole-doped 2D Hubbard model with anisotropic nearest-neighbor hopping are evaluated using the perturbation theory. The nested sections of the FS, which are always present in the anisotropic model, are found to expand with the strength of Coulomb correlation U. The renormalized FS and the low-energy part of the density of states obtained for small anisotropy and large U are similar to those obtained for large anisotropy and small U. The effect of correlation at low doping can best be described as an enhancement of the hopping anisotropy. The anomalous spectral features are mainly due to the van Hove singularities, which give rise to the momentum dependence of the self-energy.
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