High-energy scale revival and giant kink in the dispersion of a cuprate superconductor

TL;DR

This study reveals a large-scale, well-matched band dispersion and a giant kink in a cuprate superconductor, providing new insights into its electronic structure through photoemission analysis.

Contribution

It uncovers a large-scale dispersion following band calculations and extracts the full self-energy, advancing understanding of cuprate electronic properties.

Findings

Large-scale dispersion closely matches band structure calculations.

Observation of a giant kink in the electronic dispersion.

Extraction of the complete self-energy in the low energy region.

Abstract

In the present photoemission study of a cuprate superconductor Bi1.74Pb0.38Sr1.88CuO6+delta, we discovered a large scale dispersion of the lowest band, which unexpectedly follows the band structure calculation very well. The incoherent nature of the spectra suggests that the hopping-dominated dispersion occurs possibly with the assistance of local spin correlations. A giant kink in the dispersion is observed, and the complete self-energy containing all interaction information is extracted for a doped cuprate in the low energy region. These results recovered significant missing pieces in our current understanding of the electronic structure of cuprates.