Abstract
Intersubband polarization couples to collective excitations of the interacting electron gas confined in a semiconductor quantum well (QW) structure. Such excitations include correlated pair excitations (repellons) and intersubband plasmons. The oscillator strength of intersubband resonances (ISBRs) strongly varies with QW parameters and electron density because of this coupling. Using the intersubband semiconductor Bloch equations for a two-conduction-subband model, we show that intersubband absorption spectra for narrow wells are dominated by the Fermi-edge singularity (via coupling to repellons) when the electron gas becomes degenerate and in the presence of large nonparabolicity. Thus the resonance peak position appears at the Fermi edge and the peak is greatly narrowed, enhanced, and red shifted as compared to the free particle result. Our results uncover a new perspective for ISBRs and indicate the necessity of proper many-body theoretical treatment in order for modeling and prediction of ISBR line shape.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 264-267 |
| Number of pages | 4 |
| Journal | Physica E: Low-Dimensional Systems and Nanostructures |
| Volume | 20 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Jan 2004 |
| Externally published | Yes |
| Event | Proceedings of the 11th International Conference on Narrow Gap - Buffalo, NY., United States Duration: Jun 16 2003 → Jun 20 2003 |
Keywords
- Intersubband resonance
- Many-body effects
- Nonparabolicity
- Quantum wells
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics