Lattice Dynamics and Electron Pairing in High Temperature

Abstract: Angle resolved photoemission spectroscopy combined with isotope substitution (16O®18O) sample preparation method is used to probe the effect of the lattice degrees of freedom on the electron dynamics of optimally doped Bi2Sr2CaC2O8+d high temperature superconductors, as a function of momentum and temperature. Our data show that the lattice dynamics strongly renormalizes the electron dispersion and the photoemission line shapes. The renormalization is enhanced near the anti-nodal region and in the superconducting state, i.e. as the superconducting gap opens up. This unusual behavior is direct evidence that the electron-phonon interaction is correlated with the electron pairing in the high temperature superconductivity. Key words: High Temperature Superconductors, ARPES, coherent quasiparticle, incoherent quasiparticle, isotope substitution. One of the ongoing debates in the field of high temperature superconductors is whether the lattice degrees of freedom are responsible for some of the unusual electronic properties of the cuprates. While many experiments have pointed out that the lattice is heavily involved in severa