The hierarchy of multiple many-body interaction scales in high-temperature superconductors

TL;DR

This paper uses advanced photoemission spectroscopy to identify a hierarchy of many-body interaction energy scales in high-temperature superconductors, revealing universal and doping-dependent features from low to high energies.

Contribution

It uncovers multiple energy scales of many-body interactions in high-Tc superconductors, extending analysis to higher energies and doping dependence beyond previous studies.

Findings

Identification of three distinct energy anomalies: 0.03-0.09 eV, 0.3-0.5 eV, and ~2 eV.

Universal behavior of anomalies across different superconductor families.

Doping dependence observed in all three energy scales.

Abstract

To date, angle-resolved photoemission spectroscopy has been successful in identifying energy scales of the many-body interactions in correlated materials, focused on binding energies of up to a few hundred meV below the Fermi energy. Here, at higher energy scale, we present improved experimental data from four families of high-Tc superconductors over a wide doping range that reveal a hierarchy of many-body interaction scales focused on: the low energy anomaly ("kink") of 0.03-0.09eV, a high energy anomaly of 0.3-0.5eV, and an anomalous enhancement of the width of the LDA-based CuO2 band extending to energies of ~ 2 eV. Besides their universal behavior over the families, we find that all of these three dispersion anomalies also show clear doping dependence over the doping range presented.