Strong Influence of Phonons on the Electron Dynamics of Bi2212

TL;DR

This study investigates the origin of the 'kink' in electron dispersion in Bi2212 superconductors, providing evidence that phonons significantly influence electron dynamics across different momentum regions.

Contribution

It offers new insights into the momentum-dependent behavior of the kink and highlights the strong role of phonons in high-temperature superconductivity.

Findings

Temperature dependence of the kink is consistent with phonon involvement.

The kink structure varies from nodal to anti-nodal regions.

Phonons contribute strongly to electron dynamics in Bi2212.

Abstract

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 Bi2212 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.