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Systematic Mapping of the Hubbard Model to the Generalized t-J Model

Alexander Reischl·Erwin Müller-Hartmann·Götz S. Uhrig
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Abstract

The generalized t-J model conserving the number of double occupancies is constructed from the Hubbard model at and in the vicinity of half-filling at strong coupling. The construction is realized by a self-similar continuous unitary transformation. The flow equation is closed by a truncation scheme based on the spatial range of processes. We analyze the conditions under which the t-J model can be set up and we find that it can only be defined for sufficiently large interaction. There, the parameters of the effective model are determined.

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Alexander Reischl, Erwin Müller-Hartmann, Götz S. Uhrig. 2005-01-04. Systematic Mapping of the Hubbard Model to the Generalized t-J Model. https://doi.org/10.1103/physrevb.70.245124

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