In the optical conductivity of four different manganites with commensurate charge order (CO), strong peaks appear in the meV range below the ordering temperature TCO. They are similar to those reported for one-dimensional charge density waves (CDW) and are assigned to pinned phasons. The peaks and their overtones allow one to obtain, for La1-n/8Can/8MnO3 with n=5, 6, the electron-phonon coupling, the effective mass of the CO system, and its contribution to the dielectric constant. These results support a description of the CO in La-Ca manganites in terms of moderately weak coupling and of the CDW theory.
Observation of Charge-Density-Wave Excitations in Manganites / Nucara, Alessandro; Maselli, Paola; Calvani, Paolo; R., Sopracase; Ortolani, Michele; G., Gruener; M., CESTELLI GUIDI; U., Shade; J., Garcia. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 101:(2008), pp. 066407-1-066407-4. [10.1103/PhysRevLett.101.066407]
Observation of Charge-Density-Wave Excitations in Manganites.
NUCARA, Alessandro;MASELLI, Paola;CALVANI, Paolo;ORTOLANI, MICHELE;
2008
Abstract
In the optical conductivity of four different manganites with commensurate charge order (CO), strong peaks appear in the meV range below the ordering temperature TCO. They are similar to those reported for one-dimensional charge density waves (CDW) and are assigned to pinned phasons. The peaks and their overtones allow one to obtain, for La1-n/8Can/8MnO3 with n=5, 6, the electron-phonon coupling, the effective mass of the CO system, and its contribution to the dielectric constant. These results support a description of the CO in La-Ca manganites in terms of moderately weak coupling and of the CDW theory.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
