The effect of temperature, magnetic impurity, and photon irradiation on ferromagnetic properties of manganese doped gallium arsenide (Ga1−xMnxAs) diluted magnetic semiconductor

This study presents a theoretical investigation of the effects of temperature, magnetic impurity concentration, and photon–magnon coupling on the ferromagnetic properties of manganese-doped gallium arsenide (Ga1−xMnxAs), a representative diluted magnetic semiconductor (DMS). Employing the equation of motion method within the Green’s function formalism, we derive analytical expressions for magnon dispersion, magnon density, reduced magnetization, and magnon heat capacity. The results show that magnon dispersion energy increases quadratically with wave vector but decreases with increasing dopant concentration due to enhanced spin stiffness. Magnon density is elevated by both temperature and photon coupling, reflecting thermally and optically induced spin excitations. The reduced magnetization decreases with temperature and photon–magnon interaction, owing to increased spin disorder, but is enhanced by moderate impurity concentrations that introduce additional magnetic moments. Magnon heat capacity increases with temperature and photon coupling strength due to hybridized magnon–photon states, while it is suppressed by higher impurity levels that limit magnon excitation. These findings highlight the tunability of magnetic and thermodynamic properties in DMS systems through controlled doping and external photon fields, offering valuable insights for the development of spintronic devices, magnetic sensors, and cavity-coupled magnetic technologies.