High-resolution ARPES study of many-body interactions in high-Tc cuprate superconductors

We report our recent ultrahigh-resolution angle-resolved photoemission spectroscopy (ARPES) results on several hole- and electron-doped high-Tc cuprate superconductors. We have studied the momentum and temperature dependence of the kink in the dispersion near the Fermi level and its “magnetic isotope effect” in hole-doped superconductors. The momentum dependence of pseudogap and superconducting gap has been studied for electron-doped superconductors. All the experimental results unambiguously indicate that the magnetic interaction is essential in characterizing the electronic structure and the superconductivity.