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Polaron and bipolaron formation in the Hubbard-Holstein model: role of next-nearest neighbor electron hopping

G. De Filippis·V. Cataudella·G. Iadonisi·V. Marigliano Ramaglia·C. A. Perroni·F. Ventriglia
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Abstract

The influence of next-nearest neighbor electron hopping, $t^{\prime}$, on the polaron and bipolaron formation in a square Hubbard-Holstein model is investigated within a variational approach. The results for electron-phonon and electron-electron correlation functions show that a negative value of $t^{\prime}$ induces a strong anisotropy in the lattice distortions favoring the formation of nearest neighbor intersite bipolaron. The role of $t^{\prime}$, electron-phonon and electron-electron interactions is briefly discussed in view of the formation of charged striped domains.

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G. De Filippis, V. Cataudella, G. Iadonisi, V. Marigliano Ramaglia, C. A. Perroni, F. Ventriglia. 2001-06-28. Polaron and bipolaron formation in the Hubbard-Holstein model: role of next-nearest neighbor electron hopping. https://doi.org/10.1103/physrevb.64.155105

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