- Tytuł:
- Spectroscopy of Charged Donors and Many-Electron Effects in Semiconductor Quantum Wells
- Autorzy:
-
McCombe, B. D.
Jiang, Z. X.
Tischler, J. G.
Weinstein, B. A.
Hawrylak, P. - Powiązania:
- https://bibliotekanauki.pl/articles/2011126.pdf
- Data publikacji:
- 1999-11
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
73.20.Dx
73.20.Hb
78.66.Fd - Opis:
- Far infrared magnetospectroscopic studies of negative donor ions (D$\text{}^{-}$), and donors in the presence of many excess electrons in high magnetic fields in GaAs/AlGaAs quantum wells are reviewed. Both singlet and triplet transitions of well-center D$\text{}^{-}$ions were observed and are in good agreement with recent theoretical calculations. For off-well-center D$\text{}^{-}$ions evidence for a predicted magnetic-field-induced "unbinding" of the second electron was found. In the presence of many excess electrons the D$\text{}^{-}$singlet and -triplet transitions are blue-shifted substantially and evolve into bound magnetoplasmon excitations. Cusps are observed at integral and fractional Landau-level filling factors (ν) in a plot of normalized blue-shift of the D$\text{}^{-}$singlet-like bound magnetoplasmon transition vs. ν. For ν<1, the singlet-like bound magnetoplasmon transition continuously approaches the isolated D$\text{}^{-}$singlet transition with increasing magnetic field, while the triplet-like transition loses strength, irrespective of the electron density. Exact diagonalization studies of a donor ion with a few electrons in a parabolic lateral confining potential show the importance of electron-electron interactions and localization due to the long-range fluctuating potential in explaining this behavior. High pressure studies in a specially designed diamond anvil cell exhibit a continuous evolution from bound magnetoplasmon transitions to isolated D$\text{}^{-}$transitions to neutral donor transitions in a single sample as the pressure is increased and the electron density in the wells is decreased.
- Źródło:
-
Acta Physica Polonica A; 1999, 96, 5; 559-572
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł