Low temperature two-dimensional mobility of a GaAs heterolayer

The two-dimensional electron mobility for a GaAs single-interface heterolayer at low temperatures is computed, as a function of electron sheet density, in terms of the Fang-Howard-Stern model wave-function, for both deformation-coupled and piezoelectric-coupled scattering by acousticmode phonons. The temperature range of validity for this mobility proportional to 1/T is estimated. The unscreened mobilities are also given for comparison. The ion-scattering mobility, for various distances of the donor ion layer from the interface, is also computed, using the same model wave-function. It appears that, in the conditions of interest, lattice scattering will not dominate the overall mobility but can have a significant effect on it.