Doping evolution of nodal electron dynamics in trilayer cuprate superconductor Bi2Sr2Ca2Cu3O10+δ revealed by laser-based angle-resolved photoemission spectroscopy

The doping evolution of the nodal electron dynamics in the trilayer cuprate superconductor Bi2Sr2Ca2Cu3O10+δ (Bi2223) is investigated using high-resolution laser-based angle-resolved photoemission spectroscopy (ARPES). Bi2223 single crystals with different doping levels are prepared by controlled annealing, which cover the underdoped, optimally-doped and overdoped regions. The electronic phase diagram of Bi2223 is established which describes the Tc dependence on the sample doping level. The doping dependence of the nodal Fermi momentum for the outer (OP) and inner (IP) CuO2 planes is determined. Charge distribution imbalance between the OP and IP CuO2 planes is quantified, showing enhanced disparity with increasing doping. Nodal band dispersions demonstrate a prominent kink at ∼ 94 meV in the IP band, attributed to the unique Cu coordination in the IP plane, while a weaker ∼ 60 meV kink is observed in the OP band. The nodal Fermi velocity of both OP and IP bands is nearly constant at ∼ 1.62 eV⋅Å independent of doping. These results provide important information to understand the origin of high Tc and superconductivity mechanism in high temperature cuprate superconductors.