Subpicosecond hot-hole relaxation in germanium studied by time-resolved inter-valence-band Raman scattering

Buildup of the Raman signal due to inter-valence-band scattering of holes was observed in the subpicosecond time scale in germanium. The buildup is attributed to the increase of holes at k≃7.9×${10}^6$ ${\mathrm{cm}}^{\mathrm{-}1}$, reflecting the cooling process. By analysis, taking the optical-phonon scattering into account, the deformation potential is obtained as ${\mathit{D}}_0$=1.0×${10}^9$ eV/cm.