Magneto-biexciton in a group III–V diluted magnetic quantum dot

Abstract

Binding energies of biexciton are computed in a GaMnAs / GaAlAs quantum dot with the effects of geometrical confinement, exchange interaction between the charge carrier and the magnetic impurities and the magnetic field. The size dependence of the binding energy of the biexciton in the presence of magnetic field is brought out. The optical transition energy, in the presence of magnetic field strength, is discussed for various magnetic impurities in a GaMn x As quantum dot. Numerical calculations are performed using variational technique. The spin polaronic energy of the biexciton with the effect of spatial confinement is carried out taking into account the mean field approximation in the presence of magnetic field strength. The magnetization of magnetic ion impurities as a function of dot radius is computed in a GaMn 0.02 As quantum dot. The effective g-factor as a function of spatial confinement is found in the GaMnAs quantum dot. The results show that the shift in spin polaron has more influence for the larger dot radius and the nonlinearity to linear behavior of g-factor for a particular dot size is achieved due to the sign reversal of Zeeman splitting.