Single impurity Anderson model and band anti-crossing in the Ga1-xInxNyAs1-y material system

The role of the single-N impurity in the GaInNAs system is evaluated using the single impurity Anderson model. The N impurities can act either as scattering resonances or as bound states depending on their energy position. For the former case, using self-energy calculations and Matsubara Green's functions we investigate the nature of the mixed single-N state (energy broadening, shift). The effect of this interaction on the perturbed conduction subbands is also examined. The single impurity Anderson model results in a complex band structure. The real part of the band structure can be directly related to the dispersion obtained with the band anti-crossing model and is in very good agreement. The imaginary bandstructure contains further information about the mixing of the nitrogen state and the conduction band which is not contained within the band anti-crossing model.