Relevance of intra- and inter-subband scattering on the absorption in   heterostructures
  We analyze the absorption lineshape for inter-subband transitions in disordered quasi 2D heterostructures by an exact calculation. The intra-subband scatterings control the central peak while the tails of the absorption line are dominated by the inter-subband scattering terms. Our numerical study quantitatively assesses the magnitude of the free carrier absorption. The accuracy of different models currently used for gain/absorption is discussed. 
Camille NDebeka-Bandou, Francesca Carosella, Robson Ferreira, Andreas   Wacker and G\'erald Bastard
cond-mat.mes-hall