Abstract
Polaronic effects are investigated in the two-dimensional t − J model (describing Cu spins and holes of the planes in high-Tc cuprates) in the presence of in-plane dynamic oxygen breathing modes. We focus on the effect of dynamic multi-phonon modes. Spin and charge structure factors are computed. We found evidence for self-localization of the holes and increased short-range antiferromagnetic spin-spin correlations between the remaining spins. This effect persists when all the in-plane oxygen vibration degrees of freedom are taken into account. This suggests that dynamic phonons could play a key role in stabilizing inhomogeneous stripe phases or domain wall structures.