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arXiv · 2007.06205

Electron pairing in the Hubbard model as a result of on-site repulsion fluctuations

Igor N. Karnaukhov
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Abstract

We focus our quantitative analysis on the stability of the insulator state in the Hubbard model at a half-filling. Taking into account large-scale fluctuations (with a long relaxation time) of the on-site Coulomb repulsion, we consider the possibility of realizing a stabile state which is characterized by pairing for electrons. The pairing mechanism is as follows: due to fluctuations of on-site repulsion of electrons, holes, as excited states, are formed electron pairs. The bare values of on-site Coulomb repulsion and its fluctuations, for which the states with electron pairing are stable, are calculated. The proposed pairing mechanism is to some extent similar to the formation of a localized moment in the Wolf model. The calculations were performed for the chain, as well as square and cubic lattices.

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Igor N. Karnaukhov. 2020-07-13. Electron pairing in the Hubbard model as a result of on-site repulsion fluctuations. https://doi.org/10.1088/2633-1357%2Fabe4b9

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