Superconductivity-induced phonon anomalies have been studied by inelastic neutron scattering for c-axis polarized modes in a single crystal of YBa2Cu3O7. a mode with B2u symmetry, which has out-of-phase motions of crystallographically distinct O(2) and O(3) atoms within a CuO2 plane, apparently exhibits a frequency decrease and a narrowing of the profile width with onset of the superconductivity, while a mode which has in-phase motions of these oxygens with respect to Cu atoms within the CuO2 plane does not show an appreciable anomaly. The (x2−y2)-like symmetry of the superconducting order parameter is suggested by considering recent theoretical arguments.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)