From Hubbard model to t-J-U model: a canonical transformation formalism, the metal-insulator transition and mean-field state

Yue Yu

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From Hubbard model to t-J-U model: a canonical transformation formalism, the metal-insulator transition and mean-field state

Yue Yu

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Abstract

We prove that the t-J-U model can be deduced from the Hubbard model at a large but finite U by a canonical transformation. We argue that the system may have a metal-insulator transition at a critical on-site Coulomb interaction whose value, however, is smaller than that in previous calculations in which the kinetic energy has a double counting. In a mean field theory and a special choice of the parameters, we show that the metallic state may be equivalent to the gossamer superconducting state proposed by Laughlin recently.

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Yue Yu. 2003-03-24. From Hubbard model to t-J-U model: a canonical transformation formalism, the metal-insulator transition and mean-field state. https://arxiv.org/abs/cond-mat/0303501

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