Quasiparticle spectra in a t-J model with electron-phonon interactions

The change of the spectral properties of the single-particle Green's function due to a coupling to optical phonons is investigated for strongly correlated electrons. Except at the bottom of the band the quasiparticle pole is considerably broadened due to phonon-induced decay processes, and phonon-satellite structures appear. The overall coherent bandwidth is, however, not significantly changed. The phonon induced mass renormalization of a single carrier which propagates in the t-J model on scale J is found to be much larger than in the corresponding uncorrelated model, except in the limit of J → 0. (orig.)