Investigation of magnetotransport properties at GaAs/AlGaAs and AlGaAs/AlAs quantum well structures

In this study, magnetotransport properties of GaAs/AlGaAs and AlGaAs/AlAs quantum well heterostructures grown by MBE technique were investigated. In order to scrutinize quality of contacts, current-voltage measurements for samples at a temperature range of 10-300 K was performed. To understand suppress scattering mechanisms and determine structures parameters, classical Hall effect measurements were carried out from 77 K to 300 K. With the aim of semtinizing magnetotransport properties of samples, magnetoresistance measurements were performed at different temperatures and different electrical fields. Quantum effects such as Shubnikov-de Haas oscillations and negative magnetoresistance at handled structures were observed and explained the reasons of these effects with different predictions. Also, comparing to experimental results with some theoretical calculations the sample parameters were determined.