Effect of parabolic potential well profile on multisubband electron mobility in a coupled quantum well in presence of an external electric field

We study the effect of parabolic potential well profile on the electric field dependent multisubband electron mobility in a double quantum well structure. We consider a barrier delta doped GaAs-AlxGa1-xAs parabolic coupled double quantum well subject to an external electric field perpendicular to the interface plane. Variation of the electric field transfers the system from double subband occupancy to single subband occupancy at which an enhancement of mobility is obtained due curtailment of the intersubband effects. It is gratifying to show that enhancement of curvature of the potential profile i.e., replacement of a square quantum well into a parabolic quantum well structure enhances the mobility through the intersubband effects. We vary the structure parameters such as well width, barrier width, doping concentration and height of the parabolic potential to analyze the effect of the parabolic well structure on the field dependent multisubband electron mobility, which shows interesting features. (C) 2013 Elsevier Ltd. All rights reserved.