{"paper":{"title":"The anomaly of the oxygen bond-bending mode at 320 cm$^{-1}$ and the additional absorption peak in the c-axis infrared conductivity of underdoped YBa$_{2}$Cu$_{3}$O$_{7-\\delta}$ single crystals revisited by ellipsometricmeasurements","license":"","headline":"","cross_cats":[],"primary_cat":"cond-mat.supr-con","authors_text":"A. Golnik, A. Wittlin, C. Bernhard, C. T. Lin, D. Munzar, J. Huml\\'i\\v{c}ek, M. Cardona","submitted_at":"1999-08-03T15:54:29Z","abstract_excerpt":"We have performed ellipsometric measurements of the far-infrared c-axis dielectric response of underdoped YBa$_{2}$Cu$_{3}$O$_{7-\\delta}$ single crystals. Here we report a detailed analysis of the temperature-dependent renormalization of the oxygen bending phonon mode at 320 cm$^{-1}$ and the formation of the additional absorption peak around 400-500 cm$^{-1}$. For a strongly underdoped YBa$_{2}$Cu$_{3}$O$_{6.5}$ crystal with T$_{c}$=52 K we find that, in agreement with previous reports based on conventional reflection measurements, the gradual onset of both features occurs well above T$_{c}$ "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"cond-mat/9908047","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}