Superconductivity-Induced Self-Energy Evolution of the Nodal Electron of Optimally-Doped Bi2212

TL;DR

This study investigates how the self-energy of nodal electrons in optimally-doped Bi2212 evolves with temperature, revealing complex electron-boson interactions and their relation to superconductivity through ARPES measurements.

Contribution

It provides new insights into the temperature-dependent self-energy evolution and demonstrates the role of multiple bosonic modes in superconductivity using a Holstein model.

Findings

Observation of fine structures in ReΣ indicating multiple bosonic couplings

Identification of a two-process evolution across the superconducting transition

Qualitative explanation of the phenomena with a Holstein model

Abstract

The temperature dependent evolution of the renormalization effect in optimally-doped Bi2212 along the nodal direction has been studied via angle-resolved photoemission spectroscopy. Fine structure is observed in the real part of the self-energy (Re$\Sigma$), including a subkink and maximum, suggesting that electrons couple to a spectrum of bosonic modes, instead of just one mode. Upon cooling through the superconducting phase transition, the fine structures of the extracted Re$\Sigma$ exhibit a two-processes evolution demonstrating an interplay between kink renormalization and superconductivity. We show that this two-process evolution can be qualitatively explained by a simple Holstein model in which a spectrum of bosonic modes is considered.