Femtosecond time-resolved pump-probe spectroscopy is used to investigate the ultrafast carrier dynamics of Ge/SiGe quantum wells grown on a Si substrate. Pronounced nonequilibrium effects in the relaxation dynamics of the optically injected carrier distributions are observed and analyzed using a microscopic many-body theory. Transient population inversion and optical gain is obtained on a femtosecond time scale for excitation at energies slightly above the lowest direct quantum-well transition.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - May 1 2009|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics