Oxygen isotope effect in optimally doped Bi2Sr2CaCu2O8+δ studied by low-energy ARPES

Abstract Using angle-resolved photoemission spectroscopy (ARPES) with low-energy tunable photons, we studied the oxygen isotope effect in optimally doped Bi 2 Sr 2 CaCu 2 O 8+ δ (Bi2212). We found the oxygen isotope shift in the real part of the electron self-energies [ReΣ( ω )s] along the nodal direction derived not only from the momentum distribution curves (MDCs) but also from the energy distribution curves (EDCs). Present results indicate straightforwardly the coupling between the nodal electrons and the phonons.