The 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-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. 
W. Meevasana, X.J. Zhou, S. Sahrakorpi, W.S. Lee, W.L. Yang, K.   Tanaka, N. Mannella, T. Yoshida, D. H. Lu, Y.L. Chen, R.H....