Author ORCID Identifier
https://orcid.org/0000-0001-5821-1511
Date of Award
Fall 12-10-2018
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Physics and Astronomy
First Advisor
Ramesh G Mani
Second Advisor
Unil Perera
Third Advisor
Alexander Kozhanov
Fourth Advisor
Vadym Apalkov
Fifth Advisor
Piet Martens
Abstract
This dissertation summarizes the experimental study of novel magnetoresistance (MR) properties in the GaAs/AlGaAs 2D electron systems (2DES). The first part of the dissertation discusses the mutual influence between current-induced (IDC ) negative-giant magnetoresistance (GMR) and radiation-induced MR oscillations. The results show that MR oscillations do not modify the negative-GMR, and the MR oscillatory extrema disappear asymmetrically with increasing IDC. The second section discusses the influence of temperature on the weak localization-like narrow negative-MR effect that appears over the interval -0.025 ≤ B ≤ 0.025 Tesla. Results suggest that the narrow negative-MR effect could be due to coherent backscattering of electrons from remote ionized donors in the GaAs/AlGaAs system. The last section analyses the influence of microwave (MW) power on the narrow negative-MR effect. It turns out that the electrons heating due to the absorption of MW radiation suppresses the narrow negative-MR effect about the null magnetic field.
DOI
https://doi.org/10.57709/13397717
Recommended Citation
Samaraweera, Rasanga L., "Effect of DC-Current and Microwave Excitations on Negative Magnetoresistance in GaAs/AlGaAs 2DES." Dissertation, Georgia State University, 2018.
doi: https://doi.org/10.57709/13397717