title: Synergistic polaron formation in the Hubbard-Holstein model at small doping.
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 2x2 cluster. Nonlocal 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 nonlocal 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.
authors.affiliation: University of Cincinnati, Cincinnati, OH 45221, USA.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Macridin
authors.forename: Brian
authors.initials: B
authors.lastname: Moritz
authors.forename: M
authors.initials: M
authors.lastname: Jarrell
authors.forename: Thomas
authors.initials: T
authors.lastname: Maier