Role of phonons in electronic and spin excitations of high-Tc superconductors

✍ Scribed by S. Tajima; J. Schützmann

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 287 KB
• Volume: 219-220
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(95)00672-9

✦ Synopsis

By using large single crystals of YBa2Cu3Or, precise temperature and doping dependence of the c-axis infrared active phonons are investigated. The effect of the superconducting gap opening on the phonon self-energy is observed for the optimally doped crystal but not for the overdoped crystal, which suggests that this effect becomes pronounced owing to a lower crystal symmetry due to oxygen deficiencies. The observed phonon anomalies for the in-plane oxygen mode above Tc in the underdoped crystals might be associated with the c-axis conductivity suppression, and cannot be an evidence for a direct coupling of phonons to the spin system. An indirect contribution of the spin gap to the phonon system is suggested by a spectral growth around 450 cm-1