Bond stretching phonon softening and kinks in the angle-resolved photoemission spectra of optimally doped Bi2Sr1.6La0.4Cu2O6+delta superconductors.
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.
Graf
J
J
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
d'Astuto
M
M
Jozwiak
C
C
Garcia
D R
DR
Saini
N L
NL
Krisch
M
M
Ikeuchi
K
K
Baron
A Q R
AQ
Eisaki
H
H
Lanzara
A
A