Interface phonon assisted transition in double quantum well

Abstract:

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.