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Brueckner-Goldstone perturbation theory for the half-filled Hubbard model in infinite dimensions

Daniel Ruhl·Florian Gebhard
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Abstract

We use Brueckner-Goldstone perturbation theory to calculate the ground-state energy of the half-filled Hubbard model in infinite dimensions up to fourth order in the Hubbard interaction. We obtain the momentum distribution as a functional derivative of the ground-state energy with respect to the bare dispersion relation. The resulting expressions agree with those from Rayleigh-Schroedinger perturbation theory. Our results for the momentum distribution and the quasi-particle weight agree very well with those obtained earlier from Feynman-Dyson perturbation theory for the single-particle self-energy. We give the correct fourth-order coefficient in the ground-state energy which was not calculated accurately enough from Feynman-Dyson theory due to the insufficient accuracy of the data for the self-energy, and find a good agreement with recent estimates from Quantum Monte-Carlo calculations.

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Daniel Ruhl, Florian Gebhard. 2006-02-28. Brueckner-Goldstone perturbation theory for the half-filled Hubbard model in infinite dimensions. https://doi.org/10.1088/1742-5468%2F2006%2F03%2Fp03015

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