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Synergistic Polaron Formation in the Hubbard-Holstein Model at Small Doping

Alexandru Macridin·Brian Moritz·Mark Jarrell·Thomas Maier
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Abstract

We study the effect of dynamical Holstein phonons on the physics of the Hubbard model at small doping using the dynamical cluster approximation on a $2\times2$ cluster. Non-local antiferromagnetic correlations are found to significantly enhance the electron-phonon coupling, resulting in polaron formation for moderate coupling strengths. At finite doping, the electron-phonon coupling is found to strongly enhance the non-local spin correlations, indicating a synergistic interplay between the electron-phonon coupling and antiferromagnetic correlations. Although it enhances the pairing interaction, the electron-phonon coupling is found to decrease the superconducting transition temperature, due to the reduction in the quasiparticle fraction.

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Alexandru Macridin, Brian Moritz, Mark Jarrell, Thomas Maier. 2006-07-24. Synergistic Polaron Formation in the Hubbard-Holstein Model at Small Doping. https://doi.org/10.1103/physrevlett.97.056402

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