Effect of electron–phonon interaction on the single-particle spectral properties of the Hubbard model

Abstract

The effect of electron–phonon interaction on quasiparticle dispersion and spectral density is considered within second order adiabatic approximation of the two-dimensional Holstein–Hubbard model. The electron–phonon interaction gives rise to a kink in the dispersion along the nodal direction of the Brillouin zone whose dependence on isotope substitution and doping is discussed in relation to recent photoemission experiments on the nodal quasiparticles in high-temperature superconductors. It is shown that various experimental features can be qualitatively explained in a framework that considers both strong correlations effect and the usual electron–phonon interaction.