ANOMALOUS PHONONS IN YBa₂Cu₃O_7-δ SUPERCONDUCTOR

The anomalous phonon properties in YBa₂Cu₃O_7-δ superconductor quenched from different temperatures were obtained by means of IR refiection spectroscopy. The analyses of the data suggest that polarons exist in the system, and this may provide a cruicial clue to the mechanism study.