Static screening approximations for calculations of intersubband electron-electron scattering rates in semiconductor quantum wells

We compare intersubband electron-electron scattering rates calculated with both dynamic and static screening models. We find that the use of the intrasubband static dielectric function in the long-wavelength limit incorrectly models the screening of the interactions involving intersubband transitions. The use of this model results in a large underestimate of the intersubband scattering rates. We present here the correct analytical form of the static dielectric function for these intersubband interactions, which takes into account the multisubband nature of the interactions.