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One-Electron Spectral Functions of the Attractive Hubbard Model for Intermediate Coupling

Maxim Yu. Kagan·Raymond Frésard·Massimiliano Capezzali·Hans Beck
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Abstract

We calculate the one-electron spectral function of the attractive (negative-$U$) Hubbard model. We work in the intermediate coupling and low density regime and obtain the self-energy in an approximate analytical form. The excitation spectrum is found to consist of three branches. The results are obtained in a framework, based on the self-consistent T-matrix approximation, which is compatible with the Mermin-Wagner theorem.

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Maxim Yu. Kagan, Raymond Frésard, Massimiliano Capezzali, Hans Beck. 1997-04-16. One-Electron Spectral Functions of the Attractive Hubbard Model for Intermediate Coupling. https://doi.org/10.1103/physrevb.57.5995

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