Far-infrared magneto-optics of electrons in low dimensional semiconductor systems

Contains fulltext : mmubn000001_101759029.pdf (publisher's version ) (Open Access)Promotores : H. van Kempen, P. Wyder en J. Perenboom111 p

Subband-Landau-level spectroscopy in GaAs-AlxGa1-xAs heterojunctions

Contains fulltext : 112844.pdf (publisher's version ) (Open Access

High-field magnetotransport in a two-dimensional electron gas in quantizing magnetic fields and intense terahertz laser fields

We present a combined experimental and theoretical study of interactions between two-dimensional electron gases (2DEGs) and terahertz (THz) free-electron lasers in the presence of quantizing magnetic fields. It is found both experimentally and theoretically that when an intense THz field and a quantizing magnetic field are applied simultaneously to a GaAs-based 2DEG in the Faraday geometry, a strong cyclotron resonance (CR) effect on top of the magnetophonon resonances can be observed by transport measurements at relatively high temperatures. With increasing radiation intensity and/or decreasing temperature, the peaks of the CR are broadened and split due to magnetophoton-phonon scatterin

A novel mechanism for parallel conduction in GaAs-(Ga,Al)As heterojunctions

Contains fulltext : 112799.pdf (publisher's version ) (Open Access

Magnetophoton-phonon scattering in two-dimensional electron gases

Free electron laser for IR expts. was employed to examine GaAs-based two-dimensional electron gases (2DEG) systems in the presence of quantizing magnetic fields and an intense laser field in the Faraday geometry. The electronic transition rate induced by magnetophoton-phonon scattering was obtained which was applied to the calcn. of the magnetotransport coeffs. in the presence of an intense radiation field. Strong magneto-optical effects were obsd. for semiconductor nanostructures such as GaAs-based 2DEG systems when the magnetic field B .apprx. 1 T, the radiation frequency f .apprx. 1 THz, and radiation intensity F0 .apprx. 1 kV/cm. These radiation conditions were studied by the current generation of the THz or far-IR free-electron lasers