The infrared and Raman spectra of High-Tc superconductors (HCTS) in the normal phase exhibit vibrational modes (IRAV) which are superimposed to a Drude background from high-mobility carriers. In the far infrared the IRAV appear as well-resolved peaks, shifted in energy with respect to the normal modes of the lattice. In the midinfrared they are grouped into a broad polaron band peaked at about 0.1 eV. At corresponding energies, in the semiconducting phase one observes bands that are unambiguously identified as polaronic. Moreover, the IRAV show remarkable correspondences with the peaks in the Eliashberg function as determined in the same systems by tunneling measurements. These results point towards the existence of two types of carriers in HCTS, one at least being polaronic in nature.
Polaronic optical absorption in semiconducting and superconducting oxides / Calvani, Paolo; Capizzi, Mario; Lupi, Stefano; Maselli, Paola; B., Ruzicka. - In: CZECHOSLOVAK JOURNAL OF PHYSICS. - ISSN 0011-4626. - STAMPA. - 46:3(1996), pp. 1247-1248. (Intervento presentato al convegno 21st International Conference on Low Temperature Physics (LT 21) tenutosi a PRAGUE, CZECH REPUBLIC nel AUG 08-14, 1996) [10.1007/bf02562738].
Polaronic optical absorption in semiconducting and superconducting oxides
CALVANI, Paolo;CAPIZZI, Mario;LUPI, Stefano;MASELLI, Paola;
1996
Abstract
The infrared and Raman spectra of High-Tc superconductors (HCTS) in the normal phase exhibit vibrational modes (IRAV) which are superimposed to a Drude background from high-mobility carriers. In the far infrared the IRAV appear as well-resolved peaks, shifted in energy with respect to the normal modes of the lattice. In the midinfrared they are grouped into a broad polaron band peaked at about 0.1 eV. At corresponding energies, in the semiconducting phase one observes bands that are unambiguously identified as polaronic. Moreover, the IRAV show remarkable correspondences with the peaks in the Eliashberg function as determined in the same systems by tunneling measurements. These results point towards the existence of two types of carriers in HCTS, one at least being polaronic in nature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
