Theeffectofmagnon-Excitoninteractiononferromag Netic Properties Of Diluted Magnetic Semiconductors (Gamnas)

Abstract

Spintronics devices, integral to modern technology, allow for the manipulation of both charge carriers and spin within a single platform, offering advantages such as non-volatility, rapid data processing, low power consumption, and high integration density. To exploit these benefits, semiconductor materials must be doped with magnetic impurities, typically transition metals, to create diluted magnetic semiconductors (DMS) with combined ferro magnetic and semiconductor characteristics. This thesis investigates the theoretical impact of temperature, dopant concentration, and magnon-exciton interaction on the magnetic properties of manganese-doped DMS materials, specifically focusing on manganese-doped GaMnAs. Employing the equation of motion approach within Green’s function formalism, a Heisenberg-type model Hamiltonian incorporating the interaction of magnons and excitons was developed and solved. Theoretical expressions linking magnon number and system mag netization to temperature, dopant concentration (with specific values of x = 0.03,0.04,0.05), and magnon-exciton coupling strength (with values of 0.3,0.4,0.5) were derived from the spectral representation of the obtained Green’s function. Our findings indicate that the total number of magnons increases with temperature and the strength of magnon-exciton coupling, while decreasing with higher dopant concentrations. System magnetization dimin ishes with increasing temperature but is boosted by higher dopant concentrations, leading to higher ferromagnetic critical temperatures. Moreover, an escalation in the strength of the magnon-exciton interaction suppresses system magnetization. This research enhances our understanding of the intricate dynamics governing DMS materials, offering valuable insights for the advancement of spintronics technology