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Large-N expansion based on the Hubbard-operator path integral representation and its application to the $t-J$ model

Adriana Foussats·Andres Greco
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Abstract

In the present work we have developed a large-N expansion for the $t-J$ model based on the path integral formulation for Hubbard-operators. Our large-N expansion formulation contains diagrammatic rules, in which the propagators and vertex are written in term of Hubbard operators. Using our large-N formulation we have calculated, for J=0, the renormalized $O(1/N)$ boson propagator. We also have calculated the spin-spin and charge-charge correlation functions to leading order 1/N. We have compared our diagram technique and results with the existing ones in the literature.

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Adriana Foussats, Andres Greco. 2002-03-12. Large-N expansion based on the Hubbard-operator path integral representation and its application to the $t-J$ model. https://doi.org/10.1103/physrevb.65.195107

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