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Anisotropy of the Energy Gap in the Insulating Phase of the U-t-t' Hubbard Model

Ph. Brune·A. P. Kampf
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Abstract

We apply a diagrammatic expansion method around the atomic limit (U >> t) for the U-t-t' Hubbard model at half filling and finite temperature by means of a continued fraction representation of the one-particle Green's function. From the analysis of the spectral function A(\vec{k},ω) we find an energy dispersion relation with a (cos k_x-cos k_y)^2 modulation of the energy gap in the insulating phase. This anisotropy is compared with experimental ARPES results on insulating cuprates.

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Ph. Brune, A. P. Kampf. 2000-05-18. Anisotropy of the Energy Gap in the Insulating Phase of the U-t-t' Hubbard Model. https://doi.org/10.1007/s100510070054

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