INVESTIGADORES
NIEVA Gladys Leonor
artículos
Título:
Anisotropic ultraviolet Raman resonance in underdoped YBa2Cu3O6.7
Autor/es:
S. BAHRS; S. MULLER; M. RUBHAUSEN; B. SCHULZ; A.R. GONI; G. NIEVA; C. THOMSEN
Revista:
PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS
Editorial:
American Physical Society
Referencias:
Año: 2006 vol. 74 p. 245191 - 245195
ISSN:
0163-1829
Resumen:
We report an inverse Raman-bleaching anomaly of oxygen-vacancy-activated phonons in underdoped YBa2Cu3O6.7 excited in resonance at 4.1 eV. These modes are closely related to modes that photobleach under visible excitation. The resonance and selection rules match the prediction from the ab in-plane anisotropy of the dielectric function, as does their growth of intensity under illumination. These properties support the oxygen-vacancy-reordering model for photoinduced changes in underdoped YBa2Cu3O7-d. We suggest that a similar coupling to anisotropic electronic resonances is responsible for the recently discovered ab anisotropies in the phonon dispersion.
