Abstract
We report on an experimental and theoretical study of intersubband relaxation of holes in p-type modulation-doped Si1-xGex/Si multiple quantum wells. The ultrafast hole dynamics is studied in pump-probe experiments with 150 fs mid-infrared pulses. For 4.4 nm wide wells (x = 0.5) the lifetime of holes in the second heavy hole subband is only 250 fs due to rapid emission of optical phonons via the deformation potential interaction. Model calculations of hole-phonon scattering give an almost identical value and point to the crucial role of cascaded scattering via an intermediate subband with light-hole-split-off symmetry.
Original language | English (US) |
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Pages (from-to) | 485-488 |
Number of pages | 4 |
Journal | Physica E: Low-Dimensional Systems and Nanostructures |
Volume | 13 |
Issue number | 2-4 |
DOIs | |
State | Published - Mar 2002 |
Externally published | Yes |
Keywords
- Intersubband relaxation
- Optical deformation potential
- SiGe quantum walls
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics