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

C. Bernhard, D. Munzar, A. Golnik +4

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 anal…