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Superconductivity in an exactly solvable Hubbard model with bond-charge interaction

Andreas Schadschneider
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Abstract

The Hubbard model with an additional bond-charge interaction $X$ is solved exactly in one dimension for the case $t=X$ where $t$ is the hopping amplitude. In this case the number of doubly occupied sites is conserved. In the sector with no double occupations the model reduces to the $U=\infty$ Hubbard model. In arbitrary dimensions the qualitative form of the phase diagram is obtained. It is shown that for moderate Hubbard interactions $U$ the model has superconducting ground states.

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Andreas Schadschneider. 1994-11-16. Superconductivity in an exactly solvable Hubbard model with bond-charge interaction. https://doi.org/10.1103/physrevb.51.10386

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