title: Bond stretching phonon softening and kinks in the angle-resolved photoemission spectra of optimally doped Bi2Sr1.6La0.4Cu2O6+delta superconductors.
abstract: We report the first measurement of the Cu-O bond stretching phonon dispersion in optimally doped Bi2Sr1.6La0.4Cu2O6+delta using inelastic x-ray scattering. We found a softening of this phonon at q=( approximately 0.25,0,0) from 76 to 60 meV, similar to the one reported in other cuprates. A comparison with angle-resolved photoemission data on the same sample revealed an excellent agreement in terms of energy and momentum between the angle-resolved photoemission nodal kink and the soft part of the bond stretching phonon. Indeed, we find that the momentum space where a 63+/-5 meV kink is observed can be connected with a vector q=(xi,0,0) with xi > or =0.22, corresponding exactly to the soft part of the bond stretching phonon.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: J
authors.initials: J
authors.lastname: Graf
authors.forename: M
authors.initials: M
authors.lastname: d'Astuto
authors.forename: C
authors.initials: C
authors.lastname: Jozwiak
authors.forename: D R
authors.initials: DR
authors.lastname: Garcia
authors.forename: N L
authors.initials: NL
authors.lastname: Saini
authors.forename: M
authors.initials: M
authors.lastname: Krisch
authors.forename: K
authors.initials: K
authors.lastname: Ikeuchi
authors.forename: A Q R
authors.initials: AQ
authors.lastname: Baron
authors.forename: H
authors.initials: H
authors.lastname: Eisaki
authors.forename: A
authors.initials: A
authors.lastname: Lanzara