Time- and frequency-resolved pump-probe optical spectroscopy is used to investigate the effects of the impulsive injection of delocalized excitations through a charge-transfer process in insulating CuGeO3. A large broadening of the charge-transfer edge is observed on the sub-ps time scale. The modification of this spectral feature cannot be attributed to the local increase in the effective temperature, as a consequence of the energy absorbed by the pump pulse. The measured modifications of the optical properties of the system are consistent with the creation of a nonthermal state, metastable on the picosecond time scale, after the pump-induced impulsive modification of the electron interactions.
|Numero di pagine||235129|
|Rivista||PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS|
|Stato di pubblicazione||Pubblicato - 2009|
- charge transfer insulator
- non-thermal state
- time-resolved optical spectroscopy