Magnetoresistance and spin-orbit interaction in complex 2DEG systems : a study of Shubnikov-de Haas oscillations

Abstract

Magnetoresistance oscillations, also known as Shubnikov-de Haas (SdH) oscil- lations, is a well-known phenomena that results from the quantization of electron orbits in the presence of a magnetic field. These oscillations have been extensively studied and are a valuable experimental tool for extracting electronic charge densi- ties and spin-orbit interaction (SOI) couplings, such as Rashba and Dresselhaus cou- plings. Although 2DEGs with large Rashba, Dresselhaus, and g-factors are available, the current theoretical picture of explaining SdH behavior is not able to account for all those factors. Our findings show that by using a Poisson summation formula, we can analyze magneto-oscillations in 2DEGS systems with Rashba, Dresselhaus, and Zeeman couplings. The Poisson summation formula naturally separates the magne- tooscillations into fast and slow components which facilitates the analysis of the spin- orbit contribution. In this Ph.D. thesis, we investigate magnetooscillations in com- plex 2DEGs using both analytical and numerical methods thus providing a unique and comprehensive approach. Using the analytical approach, we identified a new condition for the vanishing of spin-orbit-related beatings. With numerical method, we are abled to extract both SOI couplings from the SdH oscillations independently of their Zeeman strength and electrical charge density. Additionally, we found that the behavior of SdH oscillations in such systems can be greatly influenced by the an- gle at which the in-plane magnetic field is tilted. This research contributes to the ongoing process of the development of novel spintronic devices.