ARPES study of the phase diagram of superconducting BSCCO-2212 with in-situ control of surface doping*

In high-Tc cuprates, the doping of carriers into the parent Mott insulator induces unconventional superconductivity. In most materials, including the widely studied Bi-2212, the doping level p cannot be determined from the chemical composition but is rather derived from the superconducting transition temperature, Tc, which is, in turn, measured in transport, relying on the assumption that Tc dependence on doping is universal across all the cuprate families. I will present angle-resolved photoemission studies of Bi₂Sr₂CaCu₂O_8+δ single crystals cleaved and annealed in ultra-high vacuum or in ozone to reduce or increase the doping on-demand. Such in-situ annealing technique allows mapping of a wide doping range, covering not only the superconducting dome but also previously experimentally inaccessible for this material family, metallic, non-superconducting phase on the overdoped side (OD0K). Evolution of the Fermi surface with doping shows surprisingly smooth dependence across the superconducting dome while the evolution of spectroscopic features corresponding to electron-boson coupling can be continuously tracked across the entire phase diagram including the extreme overdoped region.