Electric field induced enhancement in multisubband electron mobility in strained GaAs/InGaAs double quantum well structures

Abstract

We study the effect of external electric field F in enhancing the multisubband electron mobility mediated by intersubband effects in a pseudomorphic GaAs/In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> As coupled double quantum well structure. An electric field F changes the potential profile of the structure which in turn amends the subband energy levels and wave functions. By varying F, the occupation of different subbands can be changed. As a result the system can be transformed from double subband occupancy to single subband occupancy resulting enhancement in the mobility due to the suppression of intersubband interaction. We show that the effect of the doping concentration and hence the 2D-electron density on the electric field dependence of the subband mobility yields interesting results.