Interplay between charge-lattice interaction and strong electron correlations in cuprates: phonon anomaly and spectral kinks

摘要

We investigate the interplay between strong electron correlations andcharge-lattice interaction in cuprates. The coupling between half breathingbond stretching phonons and doped holes in the t-t'-J model is studied bylimited phonon basis exact diagonalization method. Nonadiabatic electron-phononinteraction leads to the splitting of the phonon spectral function at half-wayto the zone boundary at $\vec{q}_s=\{(\pm \pi / 2, 0), (0, \pm \pi / 2) \}$ andto low energy kink feature in the electron dispersion, in agreement withexperimental observations. Another kink due to strong electron correlationeffects is observed at higher energy, depending on the strength of thecharge-lattice coupling.