Theory of high-energy features in single-particle spectra of hole-doped cuprates

Abstract

The recent angle-resolved photoemission measurements performed up to binding energies of the order of $1\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ reveal a very robust feature: The nodal quasiparticle dispersion breaks up around $0.3--0.4\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ and reappears around $0.6--0.8\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. 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 $t\text{\ensuremath{-}}J$ model, and the waterfall reflects the fact that the low energy quasiparticles are pulled out of the soft lower Hubbard band at higher binding energies.