Bare electron dispersion from photoemission experiments

TL;DR

This paper presents a method to analyze photoemission spectra in high-temperature superconductors, revealing detailed electronic structures and quasiparticle properties even in the pseudogap state.

Contribution

The authors developed a self-consistent procedure to extract the real and imaginary parts of the self-energy from photoemission data, improving understanding of quasiparticles in Bi-2212.

Findings

Established a precise relation between measured spectra and self-energy components

Confirmed the existence of well-defined quasiparticles in the pseudogap state

Validated the spectral function analysis through Kramers-Kronig consistency

Abstract

Performing an in-depth analysis of the photoemission spectra along the nodal direction of the high temperature superconductor Bi-2212 we have developed a procedure to determine the underlying electronic structure and established a precise relation of the measured quantities to the real and imaginary parts of the self-energy of electronic excitations. The self-consistency of the procedure with respect to the Kramers-Kronig transformation allows us to draw conclusions on the applicability of the spectral function analysis and on the existence of well defined quasiparticles along the nodal direction even for the underdoped Bi-2212 in the pseudogap state.