We analyse the effect of interface roughness scattering on low temperature electron mobility μ n mediated by intersubband interactions in a multisubband coupled Ga 0.5 In 0.5 P/GaAs quantum well structure. We consider a barrier δ-doped double quantum well system in which the subband electron mobility is limited by the interface roughness scattering μ IR n and ionized impurity scattering μ imp n . We analyse the effect of the intersubband interaction and coupling of subband wavefunctions through the barrier on the intrasubband and intersubband transport scattering rates. We show that the intersubband interaction controls the roughness potential of different interfaces through the dielectric screening matrix. In the case of lowest subband occupancy, the mobility is mainly governed by the interface roughness of the central barrier. Whereas when two subbands are occupied, the interface roughness of the outer barrier predominates due to intersubband effects. The influence of the intersubband interaction also exhibits interesting results on the well width up to which the interface roughness dominates in a double quantum well structure.

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We study low temperature electron transport mobility μn in a GaAs∕InxGa1−xAs double quantum well structure. Both the extreme barriers are δ doped with Si so that the electrons diffuse into the adjacent wells (InGaAs layers) forming two sheets of two-dimensional electron gas separated by a thin central barrier. The subband electron wave functions and energy levels of the coupled quantum well system are obtained numerically as a function of well width and barrier width. We have considered the effect of alloy disorder scattering and impurity scattering on μn. The screening of the scattering potentials by the 2D-electrons is obtained in terms of the static dielectric response function within the random phase approximation. The effect of screening on the alloy disorder potential, which has been normally neglected due to short range nature of the potential, has been analyzed. We have also studied the effects of the intersubband scattering and coupling of wave functions through the barrier on μn for the multisubband system.

The electron transport mobility μn in a GaAs/AlxGa1−xAs coupled double quantum well structure has been studied. The central barrier is delta-doped with Si so that we have two sheets of two dimensional electron gas separated by a positively charged donor layer. The subband electron wave functions and the energy levels are numerically obtained as a function of barrier height, barrier width, well width, and doping concentration. The screened ionized impurity potential is obtained in terms of the static dielectric response function within the random phase approximation. The effect of tunneling of electrons through the barrier, screening of ionized impurities, and intersubband scattering on μn of the double channel system is investigated. It would be interesting to compare our results for μn with experiment, when available.