MnGa Acceptor Center in GaAs (Review)

Resumo

The model of the Mn_Ga acceptor in GaAs in which initial ground state of a coupled hole Γ₈ is changed due to the antiferromagnetic exchange interaction with five 3d electrons of the Mn core is described. The acceptor energy spectrum and the wave functions of its states and also their changes under action of deformations, electric and magnetic fields are considered. Expressions are presented for the description of various properties of isolated Mn_Ga acceptors in GaAs, and the data of some experiments (changes in the \({\text{Mn}}_{{{\text{Ga}}}}^{{\text{0}}}\) luminescence and absorption spectra and polarization under uniaxial pressures and in magnetic field, EPR spectra, temperature dependence of the magnetic susceptibility, circular polarization of photoluminescence during excitation by polarized light in magnetic field, etc.) are analyzed. It is demonstrated that, in some cases, it is necessary to take into account the existence of random electric and strain fields splitting the acceptor states in the crystal. The analysis results show that this model agrees well with most of the experimental results. The exchange interaction constant is in the range of 3–5 meV.