Effect of Intersubband Interaction on Non-Linear Electron Mobility in Asymmetric AlGaAs Parabolic Double Quantum Well Structure

We study the effect of inter-subband interaction on nonlinear electron mobility $\mu$ in asymmetric $AlGaAs$ parabolic double quantum well structure. We take into account the ionized impurity $(imp-)$ and alloy disorder $(al-)$ scatterings for calculation of $\mu$. We keep well width $w2$ towards the surface side fixed and vary $\mu$ with well width $w1$ along the substrate. The mobility $\mu$ enhances with $w1$. As $w1$ increases, there is a change in the number of subbands occupied, i.e., single, double and again single. When double subband occupied the inter-subband interaction induces nonlinear behavior of $\mu$ as a function of $w1$. This is due to the cusp like the fluctuation of $imp-$ and $al-$ intersubband scattering rate matrix elements.