Interface phonon assisted transition in double quantum well

A detailed calculation of interface phonon assisted electron intersubband transition in double GaAs/ AlGaAs quantum well structure is presented. Our calculation concentrates on the lowest two subbands which can be designed to be in resonance with a given interface phonon mode. Various phonon mode profiles display quasi- symmetric or quasi- antisymmetric shapes. The quasi- antisymmetric phonon modes give rise to much larger transition rates than those assisted by quasi- symmetric ones. The transition rate reaches a maximum when the subband separation coincides with a given phonon mode energy. The calculation procedure presented here can be easily applied to the design and simulation of other low dimensional semiconductor structures, such as quantum cascade lasers.