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Effective interactions and superconductivity in the t-J model in the large-N limit

R. Zeyher·A. Greco
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Abstract

The feasibility of a perturbation expansion for Green's functions of the t-J model directly in terms of X-operators is demonstrated using the Baym- Kadanoff functional method. As an application we derive explicit expressions for the kernel of the linearized equation for the superconducting order parameter in leading order of a 1/N expansion. The linearized equation is solved numerically on a square lattice. We find that a reasonably strong instability occurs only for even frequency pairing with d-wavelike symmetry. Results for the transition temperature and the effective interaction are given as a function of doping.

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R. Zeyher, A. Greco. 1998-08-25. Effective interactions and superconductivity in the t-J model in the large-N limit. https://doi.org/10.1007/s100510050574

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