Geometrical Asymmetry Effect on Energy and Momentum Transfer Rates in a Double-quantum-well Structure: Linear Regime

We investigate theoretically the effect of spatial asymmetry on the energy and momentum transfer rates in a double-quantum-well system using balance equation approach. Our study is limited to the linear regime where the applied electric field is sufficiently weak. We calculate the screened potential by using the random phase approximation and Hubbard approximation for the cases of high and low electron densities, respectively. Our numerical results predict that the spatial asymmetry affects considerably both the energy transfer and drag rates as a result of changes in plasmon modes. Also, we find that the spatial asymmetry effect disappears at lower temperatures by inclusion the short-range interaction.