Theory of high energy features in angle-resolved photo-emission spectra of hole-doped cuprates
Qiang-Hua Wang
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, 210093, P.R. China

The recent angle-resolved photoemission measurements performed up to binding energies of the order of 1 eV reveals a very robust feature: the nodal quasi-particle dispersion breaks up around 0.3-0.4 eV and reappears around 0.6-0.8 eV. The intensity map in the energy-momentum
space shows a waterfall like feature between these two energy scales. We demonstrated that these experimental features may follow naturally from the strong correlation effects built in the familiar t-J model, and the waterfall reflects the fact that the low energy quasi-particles are pulled out of the soft lower Hubbard band at higher binding energies.