Electron Transport in Low Dimensional Systems

Sammanfattning: This thesis consists of experimental studies of transport properties in high mobility two dimensional electron gases (2DEGs). Two material systems are used, an AlGaAs/GaAs heterojunction and a GaInAs/InP quantum well. The AlGaAs/GaAs heterojunction is used for top gating, either to additionally reduce the dimensionality of the 2DEG to observe one dimensional effects, or to explore the edge channel picture employed to describe electron transport in high magnetic fields. For the other materials system, the GaInAs/InP quantum well, a complete description of the development of a heterostructure were the highest electron mobility ever achieved in a ternary material is given. In addition, several transport effects introduced by the special qualities of the ternary semiconductor, GaInAs, such as alloy-disorder scattering and the pinning of the Fermi level in the conduction band, are discussed.