Strong influence of phonons on the electron dynamics of Bi2Sr2CaCu2O8+δ Original Research Article

The sudden change of the velocity, so-called ‘kink’, of the dispersing peak in angle resolved photoelectron spectroscopy is a well-known feature in the high-temperature superconducting cuprates. Currently, the origin of the kink is being much debated, but a consensus has not emerged yet. Here, we present a study of the momentum evolution of the kink structure from the nodal region towards the anti-nodal region, for optimally doped Bi2Sr2CaCu2O8+δ sample. We show that the observed temperature dependence of the kink structure in both regions of the momentum space is consistent with a scenario in which phonons contribute strongly to the kink.