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Renormalization of the electron-phonon coupling in the one-band Hubbard model

Erik Koch·Roland Zeyher
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Abstract

We investigate the effect of electronic correlations on the coupling of electrons to Holstein phonons in the one-band Hubbard model. We calculate the static electron-phonon vertex within linear response of Kotliar-Ruckenstein slave-bosons in the paramagnetic saddle-point approximation. Within this approach the on-site Coulomb interaction U strongly suppresses the coupling to Holstein phonons at low temperatures. Moreover the vertex function does not show particularly strong forward scattering. Going to larger temperatures kT\sim t we find that after an initial decrease with U, the electron-phonon coupling starts to increase with U, confirming a recent result of Cerruti, Cappelluti, and Pietronero. We show that this behavior is related to an unusual reentrant behavior from a phase separated to a paramagnetic state upon decreasing the temperature.

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Erik Koch, Roland Zeyher. 2004-01-07. Renormalization of the electron-phonon coupling in the one-band Hubbard model. https://doi.org/10.1103/physrevb.70.094510

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