Hierarchy of multiple many-body interaction scales in high-temperature superconductors

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-T-c superconductors over a wide doping range that reveal a hierarchy of many-body interaction scales focused on: the low-energy anomaly (kink) of 0.03-0.09 eV, a high-energy anomaly of 0.3-0.5 eV, and an anomalous enhancement of the width of the local-density-approximation-based CuO2 band extending to energies of approximate to 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.