The Study Of Photon Induced Ferromagnetism In Manganese Doped Gallium Arsenide (Gaxmn1−Xas) Diluted Magnetic Semiconductor

Abstract

This thesis investigates the effects of temperature, magnetic impurity concentration, and photon irradiation on the ferromagnetic properties of manganese-doped GaAs diluted magnetic semiconductors. By employing the equation of motion approach within the Green function formalism, we derived theoretical expressions for magnon energy dispersion, magnon density, system magnetization, and magnon heat capacity. Our findings reveal that magnon dispersion energy increases quadratically with wave vector but is suppressed with higher impurity concentrations, indicating altered spin interactions in the material. Temperature elevation enhances magnon density due to increased thermal disruption of magnetic ordering, while photon irradiation further amplifies magnon density through spin scattering. Moreover, increased magnetic impurity concentration enhances the system’s magnetization by introducing additional magnetic spins that promote magnetic ordering, although excessive impurity levels may introduce competing effects such as antiferromagnetic interactions. Conversely, magnetization decreases with rising temperatures and photon coupling strength due to competing thermal and photon energies. These results highlight the critical roles of doping, temperature control, and photon management in optimizing the magnetic properties of diluted magnetic semiconductors, with significant implications for the advancement of spintronic devices, magnetic sensors, and data storage technologies. This research contributes to a deeper understanding of the dynamic interplay between external factors and the intrinsic magnetic properties of semiconductor materials, providing a foundation for future technological advancements.