Abstract
The phonon dispersions of along the direction have been determined by inelastic x-ray scattering. Compared to the undoped parent compound, the two highest longitudinal phonon branches, associated with the Cu-O bond stretching and out-of-plane oxygen vibration, are shifted to lower energies. Moreover, an anomalous softening of the bond-stretching band is observed at about . These signatures provide evidence for strong electron-phonon coupling in this electron-doped high-temperature superconductor.
- Received 22 October 2001
DOI:https://doi.org/10.1103/PhysRevLett.88.167002
©2002 American Physical Society